CONTRAINDICATIONS / PRECAUTIONS
Acetaminophen hypersensitivity, opiate agonist hypersensitivity
Acetaminophen is contraindicated in patients with a known acetaminophen hypersensitivity, codeine hypersensitivity, or hypersensitivity to any of the excipients of the formulation to be used. Acetaminophen hypersensitivity reactions are rare, but severe sensitivity reactions are possible. Patients who have experienced a serious skin reaction with acetaminophen should not take the drug again. Although true opiate agonist hypersensitivity is rare, patients who have demonstrated a prior hypersensitivity reaction to other opioid agonists of the phenanthrene subclass including oxycodone, dihydrocodeine, hydrocodone, and morphine should not receive codeine.
Accidental exposure, alcoholism, depression, ethanol intoxication, hepatic disease, hepatitis, hepatotoxicity, hypovolemia, malnutrition, opioid overdose, opioid use disorder, potential for overdose or poisoning, requires an experienced clinician, substance abuse
Acetaminophen has the potential for overdose or poisoning causing hepatotoxicity and acute liver failure, at times resulting in liver transplantation and death. Most cases of liver injury are associated with the use of acetaminophen at doses exceeding 4 g/day and often involve the use of more than 1 acetaminophen-containing product. Use caution during the measurement of oral liquid dosage forms to minimize the risk of dosing errors that can result in accidental overdose. Advise patients receiving acetaminophen to carefully read OTC and prescription labels, to avoid excessive and/or duplicate medications, and to seek medical help immediately if more than 4 g/day of acetaminophen is ingested, even if they feel well. It is important to note that the risk of acetaminophen-induced hepatotoxicity is increased in patients with pre-existing hepatic disease (e.g., hepatitis), those who ingest alcohol (e.g., ethanol intoxication, alcoholism), those with chronic malnutrition, and those with severe hypovolemia. In patients with chronic hepatic disease, acetaminophen can be used safely in recommended doses and is often preferred to nonsteroidal anti-inflammatory drugs (NSAIDs) due to the absence of platelet impairment, gastrointestinal toxicity, and nephrotoxicity. Though the half-life of acetaminophen may be prolonged, repeated dosing does not result in drug or metabolite accumulation. In addition, cytochrome P450 activity is not increased and glutathione stores are not depleted in hepatically impaired patients taking therapeutic doses, therefore toxic metabolite formation and accumulation is not altered. Although it is always prudent to use the smallest dose of acetaminophen for the shortest duration necessary, courses less than 2 weeks in length have been administered safely to adult patients with stable chronic liver disease. Start patients with hepatic disease with a lower than normal dosage of codeine or with longer dosing intervals and titrate slowly while monitoring for signs of hypoventilation, sedation, and hypotension. No formal studies have been conducted in patients with hepatic impairment so the pharmacokinetics of codeine in this patient population are unknown. Opioid use requires an experienced clinician who is knowledgeable about the use of opioids and how to mitigate the associated risks. Opioids expose users to the risks of addiction, abuse, and misuse, which can occur at any dosage or duration. Although the risk of addiction in any individual is unknown, it can occur in persons appropriately prescribed an opioid. Addiction can occur at recommended dosages and if the drug is misused or abused. Assess each individual's risk for opioid addiction, abuse, or misuse before prescribing an opioid, and monitor for the development of these behaviors or conditions. Risks are increased in persons with a personal or family history of substance abuse (including alcoholism) or mental illness (e.g., major depression). The potential for these risks should not prevent the proper management of pain in any given individual. Persons at increased risk may be prescribed opioids but use in such persons necessitates intensive counseling about the risks and proper use of the opioid along with intensive monitoring for signs of addiction, abuse, and misuse. Abuse and addiction are separate and distinct from physical dependence and tolerance; persons with addiction may not exhibit tolerance and symptoms of physical dependence. Opioids are sought by drug abusers and persons with addiction disorders and are subject to criminal diversion. Abuse of opioids has the potential for overdose or poisoning and death. Consider these risks when prescribing or dispensing opioids. Strategies to reduce these risks include prescribing the drug in the smallest appropriate quantity. Dosing errors may result from confusion between mg and mL when prescribing, dispensing, and administering acetaminophen; codeine oral solution. Ensure that the dose is communicated clearly and dispensed accurately. Instruct patients on how to measure the dose and to use a calibrated oral dosing device. Keep opioids out of the reach of pediatric patients, others for whom the drug was not prescribed, and pets as accidental exposure or improper use may cause respiratory failure and a fatal overdose. Accidental exposure of even a single dose of an opioid, especially by younger persons, can result in a fatal overdose. Because the risk of overdose increases as opioid doses increase, reserve titration to higher doses of an opioid for persons in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks. Do not use immediate-release opioids for an extended period unless the pain remains severe enough to require an opioid and for which alternative treatment options continue to be inadequate. Many acute pain conditions (e.g., pain occurring with surgical procedures or acute musculoskeletal injuries) require no more than a few days of an opioid. Clinical guidelines on opioid prescribing for some acute pain conditions are available. Discuss the availability of naloxone with all patients and consider prescribing it in persons who are at increased risk of opioid overdose, such as those who are also using other CNS depressants, who have a history of opioid use disorder (OUD), who have experienced a previous opioid overdose, or who have household members or other close contacts at risk for accidental exposure or opioid overdose.
Renal disease, renal failure, renal impairment
Use acetaminophen with caution in patients with severe renal impairment or renal failure. Do not administer acetaminophen more frequently than every 8 hours in patients with a CrCl less than 10 mL/minute.[32569] [42289] Some studies have suggested an association between chronic use of acetaminophen and renal effects. There is negligible evidence to suggest chronic use of acetaminophen causes analgesic nephropathy; however, there is a weak association between chronic acetaminophen use and the prevalence of chronic renal failure and end-stage renal disease.[54096] In a case-controlled study of adults with early renal failure, the regular use of acetaminophen (without aspirin) was associated with a risk of chronic renal failure that was 2.5-times higher than that for non-acetaminophen users. The risk increased with an increasing cumulative acetaminophen lifetime dose. The average dose used during periods of regular acetaminophen use also correlated with risk, as those who took at least 1.4 g/day during periods of regular use had an odds ratio for chronic renal failure of 5.3; duration of therapy was unrelated to risk.[27368] Guidelines consider acetaminophen as the non-narcotic analgesic of choice for episodic pain in patients with chronic renal disease but discourage habitual consumption.[54096] Start patients with renal failure with a lower than normal dosage of codeine or with longer dosing intervals and titrate slowly while monitoring for signs of hypoventilation, sedation, and hypotension. Codeine pharmacokinetics may be altered in patients with renal failure. Clearance may be decreased and the metabolites may accumulate to much higher plasma concentrations in patients with renal failure as compared to patients with normal renal function.
G6PD deficiency
Patients with G6PD deficiency who overdose with acetaminophen may be at increased risk for drug-induced hemolysis. Practitioners should be aware of this potential complication and monitor at-risk patients for signs and symptoms of hemolysis. Conflicting data exists on whether therapeutic doses of acetaminophen can cause hemolysis in G6PD deficient patients. However, a direct cause and effect relationship has not been well established and therefore, therapeutic doses are generally considered safe in this population.
Bone marrow suppression, immunosuppression, infection, neutropenia
Symptoms of acute infection (e.g., fever, pain) can be masked during treatment with acetaminophen in patients with bone marrow suppression, especially neutropenia, or immunosuppression.
Tobacco smoking
Tobacco smoking induces the cytochrome P450 isoenzyme CYP1A2 and may potentially increase the risk for acetaminophen-induced hepatotoxicity during overdose via enhanced generation of acetaminophen's hepatotoxic metabolite, N-acetyl-p-benzoquinoneimine (NAPQI). In a retrospective chart review of 602 patients (13 to 86 years of age) admitted for acetaminophen toxicity, current daily tobacco use was registered in 70% of patients. Multivariant analyses found tobacco smoking to be an independent risk factor for hepatotoxicity, hepatic encephalopathy, and death.
Asthma, chronic obstructive pulmonary disease (COPD), coadministration with other CNS depressants, cor pulmonale, hypoxemia, respiratory depression, respiratory insufficiency, sleep apnea
Acetaminophen; codeine is contraindicated in patients with significant respiratory depression and those with acute or severe asthma in an unmonitored setting or in the absence of resuscitative equipment. Avoid coadministration with other CNS depressants when possible, as this significantly increases the risk for respiratory depression, low blood pressure, and death. Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate; if concurrent use is necessary, use the lowest effective dosages and minimum treatment durations needed and consider prescribing naloxone. Monitor patients closely for signs or symptoms of respiratory depression and sedation. [61143] Patients with chronic obstructive pulmonary disease (COPD), cor pulmonale, respiratory insufficiency, hypoxemia, hypercapnia, or preexisting respiratory depression are at increased risk of decreased respiratory drive even at recommended doses. Patients with advanced age, cachexia, or debilitation are also at an increased risk for opioid-induced respiratory depression. Monitor such patients closely, particularly when initiating and titrating the opioid; consider the use of non-opioid analgesics in these patients. Opioids increase the risk of central sleep apnea (CSA) and sleep-related hypoxemia in a dose-dependent fashion. Consider decreasing the opioid dosage in patients with CSA. Respiratory depression, if left untreated, may cause respiratory arrest and death. Carbon dioxide retention from respiratory depression may also worsen opioid sedating effects. Careful monitoring and dose titration is required, particularly when CYP3A4 and/or CYP2D6 inhibitors or inducers are used concomitantly; concurrent use of a CYP3A4 inhibitor or discontinuation of a concurrently used CYP3A4 inducer may increase plasma codeine concentrations with subsequent greater metabolism by CYP2D6, resulting in greater morphine concentrations that may potentiate the risk of fatal respiratory depression or discontinuation of a concomitantly used CYP2D6 inhibitor may decrease plasma codeine concentrations and increase morphine concentrations that may increase the risk for respiratory depression. Management of respiratory depression may include observation, necessary supportive measures, and opioid antagonist use when indicated.
Biliary tract disease, GI obstruction, ileus, pancreatitis
Acetaminophen; codeine is contraindicated in patients with known or suspected GI obstruction, including paralytic ileus. Codeine may cause spasm of the sphincter of Oddi. Opioids may cause increases in serum amylase. Monitor patients with biliary tract disease, including acute pancreatitis, for worsening symptoms.
Abrupt discontinuation
Avoid abrupt discontinuation of codeine in a physically-dependent patient. When a patient who has been taking opioids regularly and may be physically dependent no longer requires therapy with codeine, taper the dose gradually while monitoring carefully for signs and symptoms of withdrawal. If the patient develops these signs or symptoms, raise the dose to the previous level and taper more slowly, either by increasing the interval between decreases, decreasing the amount of change in dose, or both. Consider tapering to reduced opioid dosage, or tapering and discontinuing long-term opioid therapy, when pain improves; the patient requests dosage reduction or discontinuation; pain and function are not meaningfully improved; the patient is receiving higher opioid doses without evidence of benefit from the higher dose; the patient has current evidence of opioid misuse; the patient experiences side effects that diminish quality of life or impair function; the patient experiences an overdose or other serious event (e.g., hospitalization, injury) or has warning signs for an impending event such as confusion, sedation, or slurred speech; the patient is receiving medications (e.g., benzodiazepines) or has medical conditions (e.g., lung disease, sleep apnea, liver disease, kidney disease, fall risk, advanced age) that increase risk for adverse outcomes; or the patient has been treated with opioids for a prolonged period and current benefit-harm balance is unclear. If the patient has a serious mental illness, is at high suicide risk, or has suicidal ideation, offer or arrange for consultation with a behavioral health provider before initiating a taper. In patients with opioid use disorder, offer or arrange for medication-assisted treatment. Individualize opioid tapering schedules. The longer the duration of previous opioid therapy, the longer the taper may take. Common tapers involve dose reduction of 5% to 20% every 4 weeks; a faster taper may be appropriate for some patients. Significant opioid withdrawal symptoms may indicate the need to pause or slow the taper. Opioids may be stopped, if appropriate, when taken less often than once daily. Advise patients that there is an increased risk for overdose on abrupt return to a previously prescribed higher dose; provide opioid overdose education, and consider offering naloxone. Monitor patients closely for anxiety, depression, suicidal ideation, and opioid use disorder, and offer support and referral as needed.[64906]
Brain tumor, CNS depression, coma, head trauma, increased intracranial pressure, intracranial mass
Avoid codeine use in patients with CNS depression, impaired consciousness, or coma; opioids may obscure the clinical course in a patient with a head trauma injury. Monitor patients who may be susceptible to the intracranial effect of carbon dioxide retention (e.g., those with evidence of increased intracranial pressure, brain tumor, or intracranial mass) for signs of sedation and respiratory depression, particularly when initiating codeine therapy. Codeine may reduce respiratory drive and resultant carbon dioxide retention can further increase intracranial pressure.
Driving or operating machinery
Warn patients against performing potentially hazardous activities such as driving or operating machinery unless they are tolerant to the effects of codeine and know how they will react to the medication. Codeine may impair mental or physical abilities required to perform such tasks.
Shock
Codeine may cause severe hypotension, including orthostatic hypotension and syncope in ambulatory patients. There is an increased risk in patients whose ability to maintain blood pressure has already been compromised by hypovolemia or concurrent administration of certain CNS depressant drugs (e.g., phenothiazines, general anesthetics). Monitor these patients for signs of hypotension after initiating or titrating the opioid dosage. Avoid the use of codeine in patients with circulatory shock; it may cause vasodilation that can further reduce cardiac output and blood pressure.
Seizure disorder, seizures
Monitor patients with a history of seizure disorder for worsened seizure control during codeine therapy. Codeine may increase the frequency of seizures in patients with preexisting seizure disorders and may also increase the risk of seizures occurring in other clinical settings associated with seizures.
CYP2D6 ultrarapid metabolizers
Do not use codeine in patients who are CYP2D6 ultrarapid metabolizers. Some individuals may be ultrarapid metabolizers due to a specific CYP2D6 genotype (gene duplications noted as *1/*1xN or *1/*2xN). Ultrarapid metabolizers convert codeine into morphine more rapidly and completely than other people. Higher than expected serum morphine concentrations occur due to the rapid conversion and serious toxicity including life-threatening or fatal respiratory depression may occur. The prevalence of this CYP2D6 phenotype varies widely and has been estimated at 1% to 10% in White patients, 3% to 4% in Black patients, 1% to 2% in East Asian patients (Chinese, Japanese, Korean), and may be greater than 10% in certain racial/ethnic groups (e.g., Oceanian, Northern African, Middle Eastern, Ashkenazi Jews, Puerto Rican). Approximately 7% to 10% of the White patient population lacks functional CYP2D6 activity.
Geriatric
Use acetaminophen; codeine with caution in geriatric patients, starting at the low end of the dosing range and titrating slowly. Monitor for signs of central nervous system and respiratory depression. Geriatric patients may have increased sensitivity to codeine, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and concomitant disease or other drug therapy. According to the Beers Criteria, opioids are considered potentially inappropriate medications (PIMs) in geriatric patients with a history of falls or fractures and should be avoided in these patient populations, except in the setting of severe acute pain, since opioids can produce ataxia, impaired psychomotor function, syncope, and additional falls. If an opioid must be used, consider reducing the use of other medications that increase the risk of falls and fractures and implement strategies to reduce fall risk.[63923] The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents of long-term care facilities (LTCFs). According to OBRA, daily doses of acetaminophen more than 4 g/day from all sources (alone or as part of combination products) may increase the risk of hepatotoxicity. For acetaminophen doses greater than the maximum recommended daily dose, OBRA guidelines recommend a documented assessment reflecting periodic monitoring of liver function and an indication that the benefits of therapy outweigh the risks. Monitor for adverse CNS and gastrointestinal effects, physical and psychological dependency, and unintended respiratory depression, especially in individuals with compromised pulmonary function. Some adverse effects can lead to other consequences such as falls.[60742]
Adenoidectomy, children, infants, neonates, neuromuscular disease, obesity, respiratory infection, tonsillectomy
Acetaminophen; codeine is contraindicated in neonates, infants, and children younger than 12 years and for postoperative pain management in pediatric patients younger than 18 years after a tonsillectomy and/or adenoidectomy. The American Academy of Pediatrics (AAP) recommends against the use of codeine in all pediatric patients for any indication. Avoid use in patients 12 to 18 years of age who have other risk factors for respiratory depression unless the benefits outweigh the risks. Risk factors include conditions associated with hypoventilation such as postoperative status, obstructive sleep apnea, obesity, respiratory infection, asthma, severe pulmonary disease, neuromuscular disease, and concomitant use of other respiratory depressants. When prescribing codeine for adolescents, choose the lowest effective dose for the shortest period of time and inform patients and caregivers of the risks and the signs of opioid overdose. Codeine metabolism is highly variable and unpredictable, particularly in children younger than 12 years; therapeutic response to recommended doses can range from lack of effect in poor metabolizers to fatality in ultra-rapid metabolizers. Ultra-rapid metabolizers are more likely to convert codeine to morphine quickly, leading to excessive morphine blood concentrations that can result in fatal respiratory depression. Because some children who are normal metabolizers can convert codeine to morphine at rates similar to ultra-metabolizers, this concern extends to all pediatric patients. Caution must be taken when administering acetaminophen to pediatric patients to ensure appropriate dosing. Factors that can lead to inadvertent overdoses include substituting adult acetaminophen formulations for pediatric formulations for convenience, misreading or interpreting instructions, or administering more acetaminophen due to persistent fever. Repeated overdoses of acetaminophen in infants or children in combination with decreased nutrition may lead to changes in the metabolism of acetaminophen leading to hepatotoxicity. This combination leads to decreases in sulfation, glucuronidation, and glutathione production.
MAOI therapy
Acetaminophen; codeine is contraindicated in patients receiving MAOI therapy or who have received an MAOI within the previous 14 days due to the risks for potentiation of adverse effects, including confusion, respiratory depression, and coma.
Labor, neonatal opioid withdrawal syndrome, obstetric delivery, pregnancy
Use acetaminophen; codeine during pregnancy only if the potential benefit justifies the potential risk to the fetus. Published epidemiological studies have not reported a clear association with acetaminophen use during pregnancy and birth defects, miscarriage, or adverse maternal or fetal outcomes. Large observational studies of newborns exposed to oral acetaminophen during the first trimester have not shown an increased risk for congenital malformations or major birth defects; however, these studies cannot definitely establish the absence of risk because of methodological limitations. Acetaminophen does cross the placenta and should be used during pregnancy only if the benefits to the mother outweigh the potential risks to the fetus or infant. No overall increase in fetal mortality, determined by pregnancy outcomes of mothers that overdosed on various amounts of oral acetaminophen, was apparent amongst 300 women. Treatment with acetylcysteine or methionine did not appear to affect fetal or neonatal toxicity. Of 235 infants exposed to an overdose of only acetaminophen, 168 were normal, 8 had malformations, 16 were spontaneously aborted, and 43 were electively terminated. None of the infants with malformations were exposed during the first trimester, but all of the spontaneous abortions were subsequent to first trimester exposure. Available data with codeine during human pregnancy are insufficient to inform a drug-associated risk of birth defects and miscarriage. Codeine is not recommended for use during and immediately before labor when other analgesic techniques are more appropriate. Opioids can prolong labor and obstetric delivery by temporarily reducing the strength, duration, and frequency of uterine contractions. This effect is not consistent and may be offset by an increased rate of cervical dilatation, which may shorten labor. Opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in the neonate. An opioid antagonist (e.g., naloxone) should be available for reversal of opioid-induced respiratory depression in the neonate. Further, prolonged maternal use of opioids during pregnancy may result in neonatal opioid withdrawal syndrome (NOWS). Monitor the exposed neonate for withdrawal symptoms, including irritability, hyperactivity and abnormal sleep pattern, high-pitched cry, tremor, vomiting, diarrhea, and failure to gain weight, and manage accordingly. Onset, duration, and severity of opioid withdrawal may vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination by the newborn. [55881] Guidelines recommend early universal screening of pregnant patients for opioid use and opioid use disorder at the first prenatal visit. Obtain a thorough history of substance use and review the Prescription Drug Monitoring Program to determine if patients have received prior prescriptions for opioids or other high-risk drugs such as benzodiazepines. Discuss the risks and benefits of opioid use during pregnancy, including the risk of becoming physiologically dependent on opioids, the possibility for NOWS, and how long-term opioid use may affect care during a future pregnancy.[64838] [64909] In women undergoing uncomplicated normal spontaneous vaginal birth, consider opioid therapy only if expected benefits for both pain and function are anticipated to outweigh risks to the patient. If opioids are used, use in combination with nonpharmacologic therapy and nonopioid pharmacologic therapy, as appropriate. Use immediate-release opioids instead of extended-release or long-acting opioids; order the lowest effective dosage and prescribe no greater quantity of opioids than needed for the expected duration of such pain severe enough to require opioids.[64909] For women using opioids for chronic pain, consider strategies to avoid or minimize the use of opioids, including alternative pain therapies (i.e., nonpharmacologic) and nonopioid pharmacologic treatments. Opioid agonist pharmacotherapy (e.g., methadone or buprenorphine) is preferable to medically supervised withdrawal in pregnant women with opioid use disorder.[64838] In animal reproduction studies, codeine administration during organogenesis has been shown to produce delayed ossification in the offspring of mice at 1.4 times maximum recommended human dose (MRHD) of 360 mg/day, embryolethal and fetotoxic effects in the offspring of rats and hamsters at approximately 2 to 3 times the MRHD, and cranial malformations/cranioschisis in the offspring of hamsters between 2 and 8 times the MRHD.
Breast-feeding
Breast-feeding is not recommended during treatment with acetaminophen; codeine due to the risk of serious adverse reactions including excessive sedation, respiratory depression, and death in the breast-fed infant. Monitor infants exposed to codeine through breast milk for excessive sedation and respiratory depression. Withdrawal symptoms can occur in breast-fed infants when maternal use of an opioid is stopped or when breast-feeding is stopped. Alternative analgesics that previous American Academy of Pediatrics recommendations considered as usually compatible with breast-feeding include acetaminophen, ibuprofen, and morphine. Codeine and its active metabolite, morphine, are excreted into human milk. An infant nursing from an ultra-rapid metabolizer mother taking codeine could potentially be exposed to high metabolite concentrations and experience life-threatening respiratory depression. In women with normal codeine metabolism (normal CYP2D6 activity), the amount of codeine secreted into human milk is low and dose-dependent. A healthy, 13-day-old breast-fed baby died from a morphine overdose; the baby's blood morphine concentration was 70 ng/mL. The mother was taking codeine 30 mg and acetaminophen 500 mg tablets. The mother initially took 2 tablets every 12 hours for episiotomy pain, but she took half of this dose from days 2 to 14 because of somnolence and constipation. She stored her milk on day 10 because of poor neonatal feeding; the morphine concentration in the milk was 87 ng/mL. She was determined by genetic testing to be an ultra-rapid metabolizer of codeine (heterozygous for a CYP2D6*2A allele with CYP2D6*2x2 gene duplication). There is no information on the effects of codeine on milk production. Limited published studies report acetaminophen passes rapidly into human milk with similar concentrations in the milk and plasma. Average and maximum neonatal doses of 1% and 2%, respectively, of the weight-adjusted maternal dose are reported after a single oral dose of 1,000 mg. There is a well-documented report of rash occurring in a breast-fed infant that resolved with drug discontinuation and recurred with resumption.[42289]
Infertility, reproductive risk
Chronic opioid use may influence the hypothalamic-pituitary-gonadal axis, leading to hormonal changes that may manifest as hypogonadism (gonadal suppression) and pose a reproductive risk. Although the exact causal role of opioids in the clinical manifestations of hypogonadism is unknown, patients could experience libido decrease, impotence, amenorrhea, or infertility. It is not known whether the effects on fertility are reversible. Monitor patients for symptoms of opioid-induced endocrinopathy. Patients presenting with signs or symptoms of androgen deficiency should undergo laboratory evaluation.Â
DRUG INTERACTIONS
Abacavir; Lamivudine, 3TC; Zidovudine, ZDV: (Minor) Both acetaminophen and zidovudine, ZDV undergo glucuronidation. Competition for the metabolic pathway is thought to have caused a case of acetaminophen-related hepatotoxicity. This interaction may be more clinically significant in patients with depleted glutathione stores, such as patients with acquired immunodeficiency syndrome, poor nutrition, or alcoholism.
Abiraterone: (Moderate) Concomitant use of codeine with abiraterone may increase codeine plasma concentrations, but decrease the plasma concentration of the active metabolite, morphine, resulting in reduced efficacy or symptoms of opioid withdrawal. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage increase of codeine until stable drug effects are achieved. Discontinuation of abiraterone could decrease codeine plasma concentrations and increase morphine plasma concentrations resulting in prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If abiraterone is discontinued, monitor the patient carefully and consider reducing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Abiraterone is a moderate inhibitor of CYP2D6.
Acetaminophen; Aspirin; Diphenhydramine: (Major) Reserve concomitant use of opioids and diphenhydramine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Acetaminophen; Caffeine; Pyrilamine: (Moderate) Concomitant use of opioid agonists with pyrilamine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with pyrilamine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Acetaminophen; Chlorpheniramine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Acetaminophen; Chlorpheniramine; Dextromethorphan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Acetaminophen; Chlorpheniramine; Phenylephrine : (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Acetaminophen; Dextromethorphan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Acetaminophen; Dextromethorphan; Doxylamine: (Major) Reserve concomitant use of opioids and doxylamine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Acetaminophen; Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Acetaminophen; Dextromethorphan; Phenylephrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Acetaminophen; Dextromethorphan; Pseudoephedrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Acetaminophen; Diphenhydramine: (Major) Reserve concomitant use of opioids and diphenhydramine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Acetaminophen; Hydrocodone: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
Acetaminophen; Oxycodone: (Major) Concomitant use of oxycodone with other opiate agonists may lead to additive respiratory and/or CNS depression. Hypotension, profound sedation, coma, respiratory depression, or death may occur. Prior to concurrent use of oxycodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. If a CNS depressant is used concurrently with oxycodone, a reduced dosage of oxycodone and/or the CNS depressant is recommended; use an initial dose of oxycodone at 1/3 to 1/2 the usual dosage. Monitor for sedation and respiratory depression.
Acetaminophen; Pamabrom; Pyrilamine: (Moderate) Concomitant use of opioid agonists with pyrilamine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with pyrilamine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Acetaminophen; Pentazocine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as codeine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of mu-receptor opiate agonists and reduce analgesic effects of codeine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Acrivastine; Pseudoephedrine: (Major) Avoid coadministration of opioid agonists with acrivastine due to the risk of additive CNS depression.
Adagrasib: (Moderate) Concomitant use of codeine with adagrasib may alter codeine plasma concentrations, resulting in an unpredictable effect such as reduced efficacy or symptoms of opioid withdrawal or prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage adjustment of codeine until stable drug effects are achieved. Discontinuation of adagrasib could alter codeine plasma concentrations, resulting in an unpredictable effect such as prolonged opioid adverse reactions or decreased opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If adagrasib is discontinued, monitor the patient carefully and consider adjusting the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A to norcodeine; norcodeine does not have analgesic properties. Adagrasib is a dual moderate CYP2D6 and strong CYP3A inhibitor. CYP3A inhibitors may increase codeine-related adverse effects while CYP2D6 inhibitors may reduce efficacy.
Aldesleukin, IL-2: (Moderate) Aldesleukin, IL-2 may affect CNS function significantly. Therefore, psychotropic pharmacodynamic interactions could occur following concomitant administration of drugs with significant CNS or psychotropic activity such as opiate agonists. In addition, aldesleukin, IL-2, is a CYP3A4 inhibitor and may increase oxycodone plasma concentrations and related toxicities including potentially fatal respiratory depression. If therapy with both agents is necessary, monitor patients for an extended period and adjust oxycodone dosage as necessary.
Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for signs of diminished diuresis and/or effects on blood pressure during coadministration of a thiazide diuretic and codeine; increase the dosage of the thiazide diuretic as needed. Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Opioids may also potentiate orthostatic hypotension when given concomitantly with a thiazide diuretic.
Almotriptan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with serotonin-receptor agonists. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Alosetron: (Major) Patients taking medications that decrease GI motility may be at greater risk for serious complications from alosetron, like constipation, via a pharmacodynamic interaction. Constipation is the most frequently reported adverse effect with alosetron. Alosetron, if used with drugs such as opiate agonists, may seriously worsen constipation, leading to events such as GI obstruction/impaction or paralytic ileus.
Alprazolam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines.
Alvimopan: (Moderate) Patients should not take alvimopan if they have received therapeutic doses of opiate agonists for more than seven consecutive days immediately before initiation of alvimopan therapy. Patients recently exposed to opioids are expected to be more sensitive to the effects of mu-opioid receptor antagonists and may experience adverse effects localized to the gastrointestinal tract such as abdominal pain, nausea, vomiting, and diarrhea.
Amide local anesthetics: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic may allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Amiloride: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when amiloride is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Amiloride; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when amiloride is administered with codeine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for signs of diminished diuresis and/or effects on blood pressure during coadministration of a thiazide diuretic and codeine; increase the dosage of the thiazide diuretic as needed. Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Opioids may also potentiate orthostatic hypotension when given concomitantly with a thiazide diuretic.
Amiodarone: (Moderate) Concomitant use of codeine with amiodarone may alter codeine plasma concentrations, resulting in an unpredictable effect such as reduced efficacy or symptoms of opioid withdrawal or prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage adjustment of codeine until stable drug effects are achieved. Discontinuation of amiodarone could alter codeine plasma concentrations, resulting in an unpredictable effect such as prolonged opioid adverse reactions or decreased opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If amiodarone is discontinued, monitor the patient carefully and consider adjusting the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Amiodarone is a moderate inhibitor of CYP3A4 and CYP2D6. CYP3A4 inhibitors may increase codeine-related adverse effects while CYP2D6 inhibitors may reduce efficacy.
Amitriptyline: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants.
Amlodipine: (Moderate) Monitor for an increase in codeine-related adverse reactions including sedation and respiratory depression if coadministration with amlodipine is necessary; adjust the dose of codeine if necessary. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Amlodipine is a weak CYP3A4 inhibitor. Concomitant use may result in an increase in codeine plasma concentrations, resulting in greater metabolism by CYP2D6 and increased morphine concentrations.
Amlodipine; Atorvastatin: (Moderate) Monitor for an increase in codeine-related adverse reactions including sedation and respiratory depression if coadministration with amlodipine is necessary; adjust the dose of codeine if necessary. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Amlodipine is a weak CYP3A4 inhibitor. Concomitant use may result in an increase in codeine plasma concentrations, resulting in greater metabolism by CYP2D6 and increased morphine concentrations.
Amlodipine; Benazepril: (Moderate) Monitor for an increase in codeine-related adverse reactions including sedation and respiratory depression if coadministration with amlodipine is necessary; adjust the dose of codeine if necessary. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Amlodipine is a weak CYP3A4 inhibitor. Concomitant use may result in an increase in codeine plasma concentrations, resulting in greater metabolism by CYP2D6 and increased morphine concentrations.
Amlodipine; Celecoxib: (Moderate) Concomitant use of codeine with celecoxib may increase codeine plasma concentrations, but decrease the plasma concentration of the active metabolite, morphine, resulting in reduced efficacy or symptoms of opioid withdrawal. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage increase of codeine until stable drug effects are achieved. Discontinuation of celecoxib could decrease codeine plasma concentrations and increase morphine plasma concentrations resulting in prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If celecoxib is discontinued, monitor the patient carefully and consider reducing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Celecoxib is an inhibitor of CYP2D6. (Moderate) Monitor for an increase in codeine-related adverse reactions including sedation and respiratory depression if coadministration with amlodipine is necessary; adjust the dose of codeine if necessary. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Amlodipine is a weak CYP3A4 inhibitor. Concomitant use may result in an increase in codeine plasma concentrations, resulting in greater metabolism by CYP2D6 and increased morphine concentrations.
Amlodipine; Olmesartan: (Moderate) Monitor for an increase in codeine-related adverse reactions including sedation and respiratory depression if coadministration with amlodipine is necessary; adjust the dose of codeine if necessary. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Amlodipine is a weak CYP3A4 inhibitor. Concomitant use may result in an increase in codeine plasma concentrations, resulting in greater metabolism by CYP2D6 and increased morphine concentrations.
Amlodipine; Valsartan: (Moderate) Monitor for an increase in codeine-related adverse reactions including sedation and respiratory depression if coadministration with amlodipine is necessary; adjust the dose of codeine if necessary. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Amlodipine is a weak CYP3A4 inhibitor. Concomitant use may result in an increase in codeine plasma concentrations, resulting in greater metabolism by CYP2D6 and increased morphine concentrations.
Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for an increase in codeine-related adverse reactions including sedation and respiratory depression if coadministration with amlodipine is necessary; adjust the dose of codeine if necessary. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Amlodipine is a weak CYP3A4 inhibitor. Concomitant use may result in an increase in codeine plasma concentrations, resulting in greater metabolism by CYP2D6 and increased morphine concentrations. (Moderate) Monitor for signs of diminished diuresis and/or effects on blood pressure during coadministration of a thiazide diuretic and codeine; increase the dosage of the thiazide diuretic as needed. Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Opioids may also potentiate orthostatic hypotension when given concomitantly with a thiazide diuretic.
Amobarbital: (Major) Concomitant use of codeine with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when codeine is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of codeine with a barbiturate can decrease codeine concentrations, resulting in less metabolism by CYP2D6 and decreased morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of codeine and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
Amoxapine: (Major) Concomitant use of opioid agonists with amoxapine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking amoxapine. Limit the use of opioid pain medications with amoxapine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Amoxicillin; Clarithromycin; Omeprazole: (Moderate) Concomitant use of codeine with clarithromycin may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of clarithromycin could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If clarithromycin is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Clarithromycin is a strong inhibitor of CYP3A4.
Amphetamine: (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Amphetamine; Dextroamphetamine: (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Amphetamines: (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Antacids: (Minor) Antacids can delay the oral absorption of acetaminophen, but the interactions are not likely to be clinically significant as the extent of acetaminophen absorption is not appreciably affected.
Apalutamide: (Moderate) Concomitant use of codeine with apalutamide can decrease codeine levels, resulting in less metabolism by CYP2D6 and decreased morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor for reduced efficacy of codeine and signs of opioid withdrawal; consider increasing the dose of codeine as needed. If apalutamide is discontinued, consider a dose reduction of codeine and frequently monitor for signs or respiratory depression and sedation. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Apalutamide is a strong CYP3A4 inducer.
Apomorphine: (Major) Concomitant use of opioid agonists with apomorphine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking apomorphine. Limit the use of opioid pain medications with apomorphine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression. Dopaminergic agents like apomorphine have also been associated with sudden sleep onset during activities of daily living such as driving, which has resulted in accidents in some cases. Prescribers should re-assess patients for drowsiness or sleepiness regularly throughout treatment, especially since events may occur well after the start of treatment.
Apraclonidine: (Minor) Theoretically, apraclonidine might potentiate the effects of CNS depressant drugs such as opiate agonists. Although no specific drug interactions were identified with systemic agents and apraclonidine during clinical trials, apraclonidine can cause dizziness and somnolence.
Aprepitant, Fosaprepitant: (Moderate) Concomitant use of codeine with oral, multi-day regimens of aprepitant, fosaprepitant may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of aprepitant, fosaprepitant could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If aprepitant, fosaprepitant is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Aprepitant, fosaprepitant, when administered as an oral, 3-day regimen, is a moderate inhibitor of CYP3A4. (Minor) Use caution if acetaminophen and aprepitant are used concurrently and monitor for an increase in acetaminophen-related adverse effects for several days after administration of a multi-day aprepitant regimen. Acetaminophen is a minor (10 to 15%) substrate of CYP3A4. Aprepitant, when administered as a 3-day oral regimen (125 mg/80 mg/80 mg), is a moderate CYP3A4 inhibitor and inducer and may increase plasma concentrations of acetaminophen. For example, a 5-day oral aprepitant regimen increased the AUC of another CYP3A4 substrate, midazolam (single dose), by 2.3-fold on day 1 and by 3.3-fold on day 5. After a 3-day oral aprepitant regimen, the AUC of midazolam (given on days 1, 4, 8, and 15) increased by 25% on day 4, and then decreased by 19% and 4% on days 8 and 15, respectively. As a single 125 mg or 40 mg oral dose, the inhibitory effect of aprepitant on CYP3A4 is weak, with the AUC of midazolam increased by 1.5-fold and 1.2-fold, respectively. After administration, fosaprepitant is rapidly converted to aprepitant and shares many of the same drug interactions. However, as a single 150 mg intravenous dose, fosaprepitant only weakly inhibits CYP3A4 for a duration of 2 days; there is no evidence of CYP3A4 induction. Fosaprepitant 150 mg IV as a single dose increased the AUC of midazolam (given on days 1 and 4) by approximately 1.8-fold on day 1; there was no effect on day 4. Less than a 2-fold increase in the midazolam AUC is not considered clinically important.
Aripiprazole: (Moderate) Concomitant use of opioid agonists with aripiprazole may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking aripiprazole. Limit the use of opioid pain medications with aripiprazole to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Artemether; Lumefantrine: (Moderate) Concomitant use of codeine with lumefantrine may increase codeine plasma concentrations, but decrease the plasma concentration of the active metabolite, morphine, resulting in reduced efficacy or symptoms of opioid withdrawal. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage increase of codeine until stable drug effects are achieved. Discontinuation of lumefantrine could decrease codeine plasma concentrations and increase morphine plasma concentrations resulting in prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If lumefantrine is discontinued, monitor the patient carefully and consider reducing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Lumefantrine is a moderate inhibitor of CYP2D6.
Articaine; Epinephrine: (Moderate) Coadministration of articaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue articaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic may allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Asciminib: (Moderate) Concomitant use of codeine with asciminib may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of asciminib could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If asciminib is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A to norcodeine; norcodeine does not have analgesic properties. Asciminib is a weak inhibitor of CYP3A.
Asenapine: (Moderate) Concomitant use of opioid agonists with asenapine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking asenapine. Limit the use of opioid pain medications with asenapine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Aspirin, ASA; Butalbital; Caffeine: (Major) Concomitant use of codeine with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when codeine is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of codeine with a barbiturate can decrease codeine concentrations, resulting in less metabolism by CYP2D6 and decreased morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of codeine and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
Aspirin, ASA; Butalbital; Caffeine; Codeine: (Major) Concomitant use of codeine with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when codeine is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of codeine with a barbiturate can decrease codeine concentrations, resulting in less metabolism by CYP2D6 and decreased morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of codeine and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
Aspirin, ASA; Caffeine; Orphenadrine: (Major) Concomitant use of opioid agonists with orphenadrine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with orphenadrine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Avoid prescribing opioid cough medication in patients taking orphenadrine.
Aspirin, ASA; Carisoprodol: (Major) Concomitant use of opioid agonists with carisoprodol may cause excessive sedation and somnolence. Limit the use of opioid pain medications with carisoprodol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Avoid prescribing opioid cough medication in patients taking carisoprodol.
Aspirin, ASA; Carisoprodol; Codeine: (Major) Concomitant use of opioid agonists with carisoprodol may cause excessive sedation and somnolence. Limit the use of opioid pain medications with carisoprodol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Avoid prescribing opioid cough medication in patients taking carisoprodol.
Aspirin, ASA; Citric Acid; Sodium Bicarbonate: (Minor) Antacids can delay the oral absorption of acetaminophen, but the interactions are not likely to be clinically significant as the extent of acetaminophen absorption is not appreciably affected.
Aspirin, ASA; Oxycodone: (Major) Concomitant use of oxycodone with other opiate agonists may lead to additive respiratory and/or CNS depression. Hypotension, profound sedation, coma, respiratory depression, or death may occur. Prior to concurrent use of oxycodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. If a CNS depressant is used concurrently with oxycodone, a reduced dosage of oxycodone and/or the CNS depressant is recommended; use an initial dose of oxycodone at 1/3 to 1/2 the usual dosage. Monitor for sedation and respiratory depression.
Atazanavir: (Moderate) Concomitant use of codeine with atazanavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of atazanavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If atazanavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Atazanavir is a strong inhibitor of CYP3A4.
Atazanavir; Cobicistat: (Moderate) Concomitant use of codeine with atazanavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of atazanavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If atazanavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Atazanavir is a strong inhibitor of CYP3A4. (Moderate) Concomitant use of codeine with cobicistat may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of cobicistat could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If cobicistat is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Cobicistat is a strong inhibitor of CYP3A4.
Atenolol; Chlorthalidone: (Moderate) Monitor for signs of diminished diuresis and/or effects on blood pressure during coadministration of a thiazide diuretic and codeine; increase the dosage of the thiazide diuretic as needed. Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Opioids may also potentiate orthostatic hypotension when given concomitantly with a thiazide diuretic.
Atropine: (Major) Reserve concomitant use of codeine and atropine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Atropine; Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Contraindicated) Codeine use in patients taking methylene blue or within 14 days of stopping such treatment is contraindicated due to the risk of serotonin syndrome or opioid toxicity. If urgent use of an opioid is necessary, use test doses and frequent titration of small doses of another opioid to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression. (Major) Reserve concomitant use of codeine and atropine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus. (Moderate) Monitor for signs of urinary retention or reduced gastric motility during concomitant codeine and hyoscyamine use. Concomitant use may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Atropine; Difenoxin: (Major) Reserve concomitant use of codeine and atropine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus. (Moderate) Concurrent administration of diphenoxylate/difenoxin with other opiate agonists can potentiate the CNS-depressant effects of diphenoxylate/difenoxin. Use caution during coadministration. In addition, diphenoxylate/difenoxin use may cause constipation; cases of severe GI reactions including toxic megacolon and adynamic ileus have been reported. Reduced GI motility when combined with opiate agonists may increase the risk of serious GI related adverse events.
Atropine; Edrophonium: (Major) Reserve concomitant use of codeine and atropine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Avacopan: (Moderate) Concomitant use of codeine with avacopan may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of avacopan could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If avacopan is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A to norcodeine; norcodeine does not have analgesic properties. Avacopan is a weak inhibitor of CYP3A.
Azelastine: (Major) Concomitant use of opioid agonists with azelastine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking azelastine. Limit the use of opioid pain medications with azelastine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Azelastine; Fluticasone: (Major) Concomitant use of opioid agonists with azelastine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking azelastine. Limit the use of opioid pain medications with azelastine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Azilsartan; Chlorthalidone: (Moderate) Monitor for signs of diminished diuresis and/or effects on blood pressure during coadministration of a thiazide diuretic and codeine; increase the dosage of the thiazide diuretic as needed. Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Opioids may also potentiate orthostatic hypotension when given concomitantly with a thiazide diuretic.
Baclofen: (Major) Concomitant use of opioid agonists with baclofen may cause excessive sedation and somnolence. Limit the use of opioid pain medications with baclofen to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Avoid prescribing opioid cough medication in patients taking baclofen.
Barbiturates: (Major) Concomitant use of codeine with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when codeine is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of codeine with a barbiturate can decrease codeine concentrations, resulting in less metabolism by CYP2D6 and decreased morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of codeine and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
Belladonna; Opium: (Moderate) Monitor for signs of urinary retention or reduced gastric motility during concomitant codeine and belladonna use. Concomitant use may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Belumosudil: (Moderate) Concomitant use of codeine with belumosudil may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of belumosudil could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If belumosudil is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A to norcodeine; norcodeine does not have analgesic properties. Belumosudil is a weak inhibitor of CYP3A.
Belzutifan: (Moderate) Monitor for reduced efficacy of codeine and signs of opioid withdrawal in patients who have developed physical dependence if coadministration with belzutifan is necessary; consider increasing the dose of codeine as needed. It is recommended to avoid this combination when codeine is being used for cough. If belzutifan is discontinued, consider a dose reduction of codeine and frequently monitor for signs or respiratory depression and sedation. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A to norcodeine; norcodeine does not have analgesic properties. Belzutifan is a weak CYP3A inducer. Concomitant use with belzutifan can increase norcodeine levels via increased CYP3A metabolism, resulting in decreased metabolism via CYP2D6 resulting in lower morphine levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Benazepril; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for signs of diminished diuresis and/or effects on blood pressure during coadministration of a thiazide diuretic and codeine; increase the dosage of the thiazide diuretic as needed. Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Opioids may also potentiate orthostatic hypotension when given concomitantly with a thiazide diuretic.
Bendroflumethiazide; Nadolol: (Moderate) Monitor for signs of diminished diuresis and/or effects on blood pressure during coadministration of a thiazide diuretic and codeine; increase the dosage of the thiazide diuretic as needed. Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Opioids may also potentiate orthostatic hypotension when given concomitantly with a thiazide diuretic.
Benzhydrocodone; Acetaminophen: (Major) Concomitant use of opioid agonists with benzhydrocodone may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of benzhydrocodone with opioid agonists to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If benzhydrocodone is initiated in a patient taking codeine, reduce initial dosage and titrate to clinical response. If codeine is prescribed in a patient taking benzhydrocodone, use a lower initial dose of codeine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opioid cough medications in patients taking other opioid agonists. Careful monitoring, particularly during treatment initiation and dose adjustment, is recommended during coadministration of benzhydrocodone and codeine because of the potential risk of serotonin syndrome. Discontinue benzhydrocodone if serotonin syndrome is suspected. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome.
Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Contraindicated) Codeine use in patients taking methylene blue or within 14 days of stopping such treatment is contraindicated due to the risk of serotonin syndrome or opioid toxicity. If urgent use of an opioid is necessary, use test doses and frequent titration of small doses of another opioid to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression. (Moderate) Monitor for signs of urinary retention or reduced gastric motility during concomitant codeine and hyoscyamine use. Concomitant use may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Benzphetamine: (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Benztropine: (Moderate) Monitor for signs of urinary retention or reduced gastric motility during concomitant codeine and benztropine use. Concomitant use may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Berotralstat: (Moderate) Concomitant use of codeine with berotralstat may alter codeine plasma concentrations, resulting in an unpredictable effect such as reduced efficacy or symptoms of opioid withdrawal or prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage adjustment of codeine until stable drug effects are achieved. Discontinuation of berotralstat could alter codeine plasma concentrations, resulting in an unpredictable effect such as prolonged opioid adverse reactions or decreased opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If berotralstat is discontinued, monitor the patient carefully and consider adjusting the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Berotralstat is a moderate inhibitor of CYP3A4 and CYP2D6. CYP3A4 inhibitors may increase codeine-related adverse effects while CYP2D6 inhibitors may reduce efficacy.
Bethanechol: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Bexarotene: (Moderate) Concomitant use of codeine with bexarotene can decrease codeine levels, resulting in less metabolism by CYP2D6 and decreased morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor for reduced efficacy of codeine and signs of opioid withdrawal; consider increasing the dose of codeine as needed. If bexarotene is discontinued, consider a dose reduction of codeine and frequently monitor for signs or respiratory depression and sedation. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Bexarotene is a moderate CYP3A4 inducer.
Bismuth Subcitrate Potassium; Metronidazole; Tetracycline: (Moderate) Additive constipation may be seen with concurrent use of opiate agonists and antidiarrheals. Opioids increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Bismuth Subsalicylate: (Moderate) Additive constipation may be seen with concurrent use of opiate agonists and antidiarrheals. Opioids increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Bismuth Subsalicylate; Metronidazole; Tetracycline: (Moderate) Additive constipation may be seen with concurrent use of opiate agonists and antidiarrheals. Opioids increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Bisoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for signs of diminished diuresis and/or effects on blood pressure during coadministration of a thiazide diuretic and codeine; increase the dosage of the thiazide diuretic as needed. Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Opioids may also potentiate orthostatic hypotension when given concomitantly with a thiazide diuretic.
Bosentan: (Moderate) Concomitant use of codeine with bosentan can decrease codeine levels, resulting in less metabolism by CYP2D6 and decreased morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor for reduced efficacy of codeine and signs of opioid withdrawal; consider increasing the dose of codeine as needed. If bosentan is discontinued, consider a dose reduction of codeine and frequently monitor for signs or respiratory depression and sedation. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Bosentan is a moderate CYP3A4 inducer.
Brexanolone: (Moderate) Concomitant use of brexanolone with CNS depressants like the opiate agonists may increase the likelihood or severity of adverse reactions related to sedation and additive CNS depression. Monitor for excessive sedation, dizziness, and a potential for loss of consciousness during brexanolone use.
Brexpiprazole: (Major) Concomitant use of opioid agonists with brexpiprazole may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking brexpiprazole. Limit the use of opioid pain medications with brexpiprazole to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Brigatinib: (Moderate) Monitor for reduced efficacy of codeine and signs of opioid withdrawal in patients who have developed physical dependence if coadministration with brigatinib is necessary; consider increasing the dose of codeine as needed. It is recommended to avoid this combination when codeine is being used for cough. If brigatinib is discontinued, consider a dose reduction of codeine, and frequently monitor for signs or respiratory depression and sedation. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Brigatinib is a weak CYP3A4 inducer. Concomitant use with brigatinib can increase norcodeine levels via increased CYP3A4 metabolism, resulting in decreased metabolism via CYP2D6 resulting in lower morphine levels; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Brimonidine: (Moderate) Based on the sedative effects of brimonidine in individual patients, brimonidine administration has potential to enhance the CNS depressants effects of opiate agonists.
Brimonidine; Brinzolamide: (Moderate) Based on the sedative effects of brimonidine in individual patients, brimonidine administration has potential to enhance the CNS depressants effects of opiate agonists.
Brimonidine; Timolol: (Moderate) Based on the sedative effects of brimonidine in individual patients, brimonidine administration has potential to enhance the CNS depressants effects of opiate agonists.
Brompheniramine: (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with brompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Brompheniramine; Dextromethorphan; Guaifenesin: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with brompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Brompheniramine; Dextromethorphan; Phenylephrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with brompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Brompheniramine; Phenylephrine: (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with brompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Brompheniramine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with brompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Brompheniramine; Pseudoephedrine; Dextromethorphan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with brompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Budesonide; Glycopyrrolate; Formoterol: (Moderate) Monitor for signs of urinary retention or reduced gastric motility during concomitant codeine and glycopyrrolate use. Concomitant use may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Bumetanide: (Moderate) Monitor for signs of diminished diuresis and/or effects on blood pressure during coadministration of a loop diuretic and codeine; increase the dosage of the loop diuretic as needed. Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone.
Bupivacaine Liposomal: (Moderate) Coadministration of bupivacaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue bupivacaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic may allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Bupivacaine: (Moderate) Coadministration of bupivacaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue bupivacaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic may allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Bupivacaine; Epinephrine: (Moderate) Coadministration of bupivacaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue bupivacaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic may allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Bupivacaine; Lidocaine: (Moderate) Coadministration of bupivacaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue bupivacaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Moderate) Coadministration of lidocaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue lidocaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic may allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Bupivacaine; Meloxicam: (Moderate) Coadministration of bupivacaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue bupivacaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic may allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Buprenorphine: (Major) Avoid concomitant use of codeine and a mixed opioid agonist/antagonist, such as buprenorphine, due to risk for reduced analgesic effect of codeine and/or precipitation of withdrawal symptoms.
Buprenorphine; Naloxone: (Major) Avoid concomitant use of codeine and a mixed opioid agonist/antagonist, such as buprenorphine, due to risk for reduced analgesic effect of codeine and/or precipitation of withdrawal symptoms.
Bupropion: (Moderate) Concomitant use of codeine with bupropion may increase codeine plasma concentrations, but decrease the plasma concentration of the active metabolite, morphine, resulting in reduced efficacy or symptoms of opioid withdrawal. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage increase of codeine until stable drug effects are achieved. Discontinuation of bupropion could decrease codeine plasma concentrations and increase morphine plasma concentrations resulting in prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If bupropion is discontinued, monitor the patient carefully and consider reducing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Bupropion is a strong inhibitor of CYP2D6.
Bupropion; Naltrexone: (Major) When naltrexone is used as adjuvant treatment of opiate or alcohol dependence, use is contraindicated in patients currently receiving opiate agonists. Naltrexone will antagonize the therapeutic benefits of opiate agonists and will induce a withdrawal reaction in patients with physical dependence to opioids. An opiate antagonist should only be administered to a patient taking codeine with clinically significant respiratory or cardiovascular depression. Also, patients should be opiate-free for at least 7-10 days prior to initiating naltrexone therapy. If there is any question of opioid use in the past 7-10 days and the patient is not experiencing opioid withdrawal symptoms and/or the urine is negative for opioids, a naloxone challenge test needs to be performed. If a patient receives naltrexone, and an opiate agonist is needed for an emergency situation, large doses of opiate agonists may ultimately overwhelm naltrexone antagonism of opiate receptors. Immediately following administration of exogenous opiate agonists, the opiate plasma concentration may be sufficient to overcome naltrexone competitive blockade, but the patient may experience deeper and more prolonged respiratory depression and thus, may be in danger of respiratory arrest and circulatory collapse. Non-receptor mediated actions like facial swelling, itching, generalized erythema, or bronchoconstriction may occur presumably due to histamine release. A rapidly acting opiate agonist is preferred as the duration of respiratory depression will be shorter. Patients receiving naltrexone may also experience opiate side effects with low doses of opiate agonists. If the opiate agonist is taken in such a way that high concentrations remain in the body beyond the time naltrexone exerts its therapeutic effects, serious side effects may occur. (Moderate) Concomitant use of codeine with bupropion may increase codeine plasma concentrations, but decrease the plasma concentration of the active metabolite, morphine, resulting in reduced efficacy or symptoms of opioid withdrawal. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage increase of codeine until stable drug effects are achieved. Discontinuation of bupropion could decrease codeine plasma concentrations and increase morphine plasma concentrations resulting in prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If bupropion is discontinued, monitor the patient carefully and consider reducing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Bupropion is a strong inhibitor of CYP2D6.
Buspirone: (Moderate) Concomitant use of CNS depressants, such as buspirone, can potentiate the effects of codeine, which may potentially lead to respiratory depression, CNS depression, sedation, or hypotensive responses. If concurrent use of codeine and buspirone is imperative, reduce the dose of one or both drugs.
Busulfan: (Moderate) Use busulfan and acetaminophen together with caution; concomitant use may result in increased busulfan levels and increased busulfan toxicity. Separating the administration of these drugs may mitigate this interaction; avoid giving acetaminophen within 72 hours prior to or concurrently with busulfan. Busulfan is metabolized in the liver through conjugation with glutathione; acetaminophen decreases glutathione levels in the blood and tissues and may reduce the clearance of busulfan.
Butabarbital: (Major) Concomitant use of codeine with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when codeine is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of codeine with a barbiturate can decrease codeine concentrations, resulting in less metabolism by CYP2D6 and decreased morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of codeine and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
Butalbital; Acetaminophen: (Major) Concomitant use of codeine with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when codeine is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of codeine with a barbiturate can decrease codeine concentrations, resulting in less metabolism by CYP2D6 and decreased morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of codeine and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
Butalbital; Acetaminophen; Caffeine: (Major) Concomitant use of codeine with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when codeine is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of codeine with a barbiturate can decrease codeine concentrations, resulting in less metabolism by CYP2D6 and decreased morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of codeine and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
Butalbital; Acetaminophen; Caffeine; Codeine: (Major) Concomitant use of codeine with barbiturates may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with barbiturates to only patients for whom alternative treatment options are inadequate. It is recommended to avoid this combination when codeine is being used for cough. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concomitant use of codeine with a barbiturate can decrease codeine concentrations, resulting in less metabolism by CYP2D6 and decreased morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Monitor for reduced efficacy of codeine and signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. (Minor) Chronic therapy with barbiturates can increase the metabolism and decrease the effectiveness of acetaminophen. During acute overdoses, barbiturates can enhance the formation of toxic acetaminophen metabolites.
Butorphanol: (Major) Avoid the concomitant use of butorphanol and opiate agonists, such as codeine. Butorphanol is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of codeine. Butorphanol may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of butorphanol with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Calcium, Magnesium, Potassium, Sodium Oxybates: (Major) Concomitant use of opioid agonists with sodium oxybate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medication with sodium oxybate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Candesartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for signs of diminished diuresis and/or effects on blood pressure during coadministration of a thiazide diuretic and codeine; increase the dosage of the thiazide diuretic as needed. Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Opioids may also potentiate orthostatic hypotension when given concomitantly with a thiazide diuretic.
Cannabidiol: (Moderate) Concomitant use of opioid agonists with cannabidiol may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking cannabidiol. Limit the use of opioid pain medications with cannabidiol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Capsaicin; Metaxalone: (Major) Concomitant use of opioid agonists with metaxalone may cause respiratory depression, profound sedation, and death. Limit the use of opioid pain medication with metaxalone to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Avoid prescribing opioid cough medication in patients taking metaxalone. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose. Concomitant use of metaxalone and opioid agonists increases the risk for serotonin syndrome. Avoid concomitant use if possible and monitor for serotonin syndrome if use is necessary.
Captopril; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for signs of diminished diuresis and/or effects on blood pressure during coadministration of a thiazide diuretic and codeine; increase the dosage of the thiazide diuretic as needed. Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Opioids may also potentiate orthostatic hypotension when given concomitantly with a thiazide diuretic.
Carbamazepine: (Moderate) Concomitant use of codeine with carbamazepine can decrease codeine levels, resulting in less metabolism by CYP2D6 and decreased morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor for reduced efficacy of codeine and signs of opioid withdrawal; consider increasing the dose of codeine as needed. If carbamazepine is discontinued, consider a dose reduction of codeine and frequently monitor for signs or respiratory depression and sedation. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Carbamazepine is a strong CYP3A4 inducer. (Minor) Carbamazepine may potentially accelerate the hepatic metabolism of acetaminophen. In addition, due to enzyme induction, carbamazepine may increase the risk for acetaminophen-induced hepatotoxicity via generation of a greater percentage of acetaminophen's hepatotoxic metabolite, NAPQI. Clinicians should be alert to decreased effect of acetaminophen. Dosage adjustments may be necessary, and closer monitoring of clinical and/or adverse effects is warranted.
Carbinoxamine: (Moderate) Concomitant use of opioid agonists with carbinoxamine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with carbinoxamine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Carbinoxamine; Dextromethorphan; Pseudoephedrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Concomitant use of opioid agonists with carbinoxamine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with carbinoxamine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Carbinoxamine; Phenylephrine: (Moderate) Concomitant use of opioid agonists with carbinoxamine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with carbinoxamine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Carbinoxamine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with carbinoxamine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with carbinoxamine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Cariprazine: (Moderate) Concomitant use of opioid agonists lik codeine with cariprazine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with cariprazine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Avoid prescribing opioid cough medication in patients taking cariprazine.
Carisoprodol: (Major) Concomitant use of opioid agonists with carisoprodol may cause excessive sedation and somnolence. Limit the use of opioid pain medications with carisoprodol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Avoid prescribing opioid cough medication in patients taking carisoprodol.
Celecoxib: (Moderate) Concomitant use of codeine with celecoxib may increase codeine plasma concentrations, but decrease the plasma concentration of the active metabolite, morphine, resulting in reduced efficacy or symptoms of opioid withdrawal. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage increase of codeine until stable drug effects are achieved. Discontinuation of celecoxib could decrease codeine plasma concentrations and increase morphine plasma concentrations resulting in prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If celecoxib is discontinued, monitor the patient carefully and consider reducing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Celecoxib is an inhibitor of CYP2D6.
Celecoxib; Tramadol: (Major) Concomitant use of codeine with tramadol may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of codeine with tramadol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Additionally, monitor patients for seizures and/or the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. (Moderate) Concomitant use of codeine with celecoxib may increase codeine plasma concentrations, but decrease the plasma concentration of the active metabolite, morphine, resulting in reduced efficacy or symptoms of opioid withdrawal. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage increase of codeine until stable drug effects are achieved. Discontinuation of celecoxib could decrease codeine plasma concentrations and increase morphine plasma concentrations resulting in prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If celecoxib is discontinued, monitor the patient carefully and consider reducing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Celecoxib is an inhibitor of CYP2D6.
Cenobamate: (Moderate) Concomitant use of codeine with cenobamate may cause excessive sedation and somnolence. Limit the use of codeine with cenobamate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression. Avoid prescribing codeine cough medication in patients taking cenobamate. Additionally, monitor for reduced efficacy of codeine and signs of opioid withdrawal in patients who have developed physical dependence if coadministration with cenobamate is necessary; consider increasing the dose of codeine as needed. If cenobamate is discontinued, consider a dose reduction of codeine and frequently monitor for signs of respiratory depression and sedation. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Cenobamate is a moderate CYP3A4 inducer. Concomitant use with cenobamate can increase norcodeine concentrations via increased CYP3A4 metabolism, resulting in decreased metabolism via CYP2D6 resulting in lower morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Ceritinib: (Moderate) Concomitant use of codeine with ceritinib may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6 and, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of ceritinib could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If ceritinib is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Ceritinib is a strong inhibitor of CYP3A4.
Cetirizine: (Major) Reserve concomitant use of opioids and cetirizine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Cetirizine; Pseudoephedrine: (Major) Reserve concomitant use of opioids and cetirizine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Charcoal: (Minor) Activated charcoal binds many drugs within the gut. Administering charcoal dietary supplements at the same time as a routine acetaminophen dosage would be expected to interfere with the analgesic and antipyretic efficacy of acetaminophen. Charcoal is mostly used in the setting of acetaminophen overdose; however, patients should never try to treat an acetaminophen overdose with charcoal dietary supplements. Advise patients to get immediate medical attention for an acetaminophen overdose.
Chlophedianol; Dexbrompheniramine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with dexchlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexchlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chloramphenicol: (Moderate) Concomitant use of codeine with chloramphenicol may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of chloramphenicol could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If chloramphenicol is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Chloramphenicol is a strong inhibitor of CYP3A4.
Chlorcyclizine: (Moderate) Concomitant use of opioid agonists with chlorcyclizine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorcyclizine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlordiazepoxide: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines.
Chlordiazepoxide; Amitriptyline: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines. (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants.
Chlordiazepoxide; Clidinium: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines.
Chloroprocaine: (Moderate) Coadministration of chloroprocaine with oxidizing agents, such as acetaminophen, may increase the risk of developing methemoglobinemia. Monitor patients closely for signs and symptoms of methemoglobinemia if coadministration is necessary. If methemoglobinemia occurs or is suspected, discontinue chloroprocaine and any other oxidizing agents. Depending on the severity of symptoms, patients may respond to supportive care; more severe symptoms may require treatment with methylene blue, exchange transfusion, or hyperbaric oxygen. (Minor) Due to the CNS depression potential of all local anesthetics, they should be used with caution with other agents that can cause respiratory depression, such as opiate agonists.
Chlorothiazide: (Moderate) Monitor for signs of diminished diuresis and/or effects on blood pressure during coadministration of a thiazide diuretic and codeine; increase the dosage of the thiazide diuretic as needed. Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Opioids may also potentiate orthostatic hypotension when given concomitantly with a thiazide diuretic.
Chlorpheniramine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Codeine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Dextromethorphan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Hydrocodone: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression. (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Ibuprofen; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Phenylephrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpromazine: (Major) Concomitant use of opioid agonists with chlorpromazine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking chlorpromazine. Limit the use of opioid pain medications with chlorpromazine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Chlorthalidone: (Moderate) Monitor for signs of diminished diuresis and/or effects on blood pressure during coadministration of a thiazide diuretic and codeine; increase the dosage of the thiazide diuretic as needed. Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Opioids may also potentiate orthostatic hypotension when given concomitantly with a thiazide diuretic.
Chlorthalidone; Clonidine: (Major) Concomitant use of opioid agonists with clonidine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with clonidine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. (Moderate) Monitor for signs of diminished diuresis and/or effects on blood pressure during coadministration of a thiazide diuretic and codeine; increase the dosage of the thiazide diuretic as needed. Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Opioids may also potentiate orthostatic hypotension when given concomitantly with a thiazide diuretic.
Chlorzoxazone: (Major) Concomitant use of opioid agonists with chlorzoxazone may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorzoxazone to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Avoid prescribing opioid cough medication in patients taking chlorzoxazone.
Cholestyramine: (Moderate) Cholestyramine has been shown to decrease the absorption of acetaminophen by roughly 60%. Experts have recommended that cholestyramine not be given within 1 hour of acetaminophen if analgesic or antipyretic effect is to be achieved.
Choline Salicylate; Magnesium Salicylate: (Moderate) Prolonged concurrent use of acetaminophen and salicylates is not recommended. Although salicylates are rarely associated with nephrotoxicity, high-dose, chronic administration of salicylates combined other analgesics, including acetaminophen, significantly increases the risk of analgesic nephropathy, renal papillary necrosis, and end-stage renal disease. Additive hepatic toxicity may occur, especially in combined overdose situations. Do not exceed the recommended individual maximum doses when these agents are given concurrently for short-term therapy.
Cimetidine: (Minor) Cimetidine may inhibit the conversion of codeine to morphine, codeine's active metabolite, via the CYP2D6 hepatic isoenzyme and therefore may decrease the ability for codeine to produce analgesic effect.
Cinacalcet: (Moderate) Concomitant use of codeine with cinacalcet may increase codeine plasma concentrations, but decrease the plasma concentration of the active metabolite, morphine, resulting in reduced efficacy or symptoms of opioid withdrawal. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage increase of codeine until stable drug effects are achieved. Discontinuation of cinacalcet could decrease codeine plasma concentrations and increase morphine plasma concentrations resulting in prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If cinacalcet is discontinued, monitor the patient carefully and consider reducing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A to norcodeine; norcodeine does not have analgesic properties. Cinacalcet is a moderate inhibitor of CYP2D6.
Ciprofloxacin: (Moderate) Concomitant use of codeine with ciprofloxacin may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6 and, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of ciprofloxacin could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If ciprofloxacin is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Ciprofloxacin is a moderate inhibitor of CYP3A4.
Citalopram: (Moderate) Serotonin syndrome can occur during concomitant use of opiate agonists like codeine with serotonergic drugs, such as citalopram. Symptoms may occur hours to days after concomitant use, particularly after dose increases. Serotonin syndrome may occur within recommended dose ranges. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Clarithromycin: (Moderate) Concomitant use of codeine with clarithromycin may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of clarithromycin could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If clarithromycin is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Clarithromycin is a strong inhibitor of CYP3A4.
Clemastine: (Moderate) Concomitant use of opioid agonists with clemastine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with clemastine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Clobazam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines.
Clomipramine: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants.
Clonazepam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines.
Clonidine: (Major) Concomitant use of opioid agonists with clonidine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with clonidine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Clopidogrel: (Moderate) Coadministration of opioid agonists, such as codeine, delay and reduce the absorption of clopidogrel resulting in reduced exposure to active metabolites and diminished inhibition of platelet aggregation. Consider the use of a parenteral antiplatelet agent in acute coronary syndrome patients requiring an opioid agonist. Coadministration of intravenous morphine decreased the Cmax and AUC of clopidogrel's active metabolites by 34%. Time required for maximal inhibition of platelet aggregation (median 3 hours vs. 1.25 hours) was significantly delayed; times up to 5 hours were reported. Inhibition of platelet plug formation was delayed and residual platelet aggregation was significantly greater 1 to 4 hours after morphine administration.
Clorazepate: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking benzodiazepines.
Clozapine: (Moderate) Concomitant use of central nervous system depressants, such as clozapine, can potentiate the effects of codeine, which may lead to respiratory depression, CNS depression, sedation, or hypotensive responses. Combining clozapine with opiate agonists may also lead to additive effects on intestinal motility or bladder function, resulting in constipation or urinary retention.
Cobicistat: (Moderate) Concomitant use of codeine with cobicistat may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of cobicistat could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If cobicistat is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Cobicistat is a strong inhibitor of CYP3A4.
Codeine; Phenylephrine; Promethazine: (Major) Concomitant use of opioid agonists with promethazine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking promethazine. Limit the use of opioid pain medications with promethazine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce the opioid dose by one-quarter to one-half; use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Codeine; Promethazine: (Major) Concomitant use of opioid agonists with promethazine may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking promethazine. Limit the use of opioid pain medications with promethazine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce the opioid dose by one-quarter to one-half; use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
COMT inhibitors: (Major) Concomitant use of opioid agonists with COMT inhibitors may cause excessive sedation and somnolence. Avoid prescribing opioid cough medications in patients taking COMT inhibitors. Limit the use of opioid pain medications with COMT inhibitors to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression. COMT inhibitors have also been associated with sudden sleep onset during activities of daily living such as driving, which has resulted in accidents in some cases. Prescribers should re-assess patients for drowsiness or sleepiness regularly throughout treatment, especially since events may occur well after the start of treatment.
Conivaptan: (Moderate) Concomitant use of codeine with conivaptan may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of conivaptan could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If conivaptan is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A to norcodeine; norcodeine does not have analgesic properties. Conivaptan is a moderate inhibitor of CYP3A.
Crizotinib: (Moderate) Concomitant use of codeine with crizotinib may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of crizotinib could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If crizotinib is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Crizotinib is a moderate inhibitor of CYP3A.
Crofelemer: (Moderate) Pharmacodynamic interactions between crofelemer and opiate agonists are theoretically possible. Crofelemer does not affect GI motility mechanisms, but does have antidiarrheal effects. Patients taking medications that decrease GI motility, such as opiate agonists, may be at greater risk for serious complications from crofelemer, such as constipation with chronic use. Use caution and monitor GI symptoms during coadministration.
Cyclizine: (Moderate) Concomitant use of opioid agonists with cyclizine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with cyclizine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Cyclobenzaprine: (Major) Concomitant use of codeine with cyclobenzaprine may cause respiratory depression, hypotension, profound sedation, and death and increase the risk for serotonin syndrome and anticholinergic effects. Limit the use of opioid pain medications with cyclobenzaprine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Avoid prescribing opioid cough medication in patients taking cyclobenzaprine. Monitor patients for serotonin syndrome if concomitant use is necessary, particularly during treatment initiation and dosage increases. If serotonin syndrome occurs, consider discontinuation of therapy. The concomitant use of serotonergic drugs increases the risk of serotonin syndrome. Monitor for signs of urinary retention or reduced gastric motility during coadministration. The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Cyclosporine: (Moderate) Concomitant use of codeine with cyclosporine may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of cyclosporine could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If cyclosporine is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Cyclosporine is a moderate inhibitor of CYP3A4.
Cyproheptadine: (Moderate) Concomitant use of opioid agonists with cyproheptadine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with cyproheptadine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Dabrafenib: (Moderate) Concomitant use of codeine with dabrafenib can decrease codeine levels, resulting in less metabolism by CYP2D6 and decreased morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor for reduced efficacy of codeine and signs of opioid withdrawal; consider increasing the dose of codeine as needed. If dabrafenib is discontinued, consider a dose reduction of codeine and frequently monitor for signs or respiratory depression and sedation. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Dabrafenib is a moderate CYP3A4 inducer.
Dacomitinib: (Moderate) Concomitant use of codeine with dacomitinib may increase codeine plasma concentrations, but decrease the plasma concentration of the active metabolite, morphine, resulting in reduced efficacy or symptoms of opioid withdrawal. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage increase of codeine until stable drug effects are achieved. Discontinuation of dacomitinib could decrease codeine plasma concentrations and increase morphine plasma concentrations resulting in prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If dacomitinib is discontinued, monitor the patient carefully and consider reducing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Dacomitinib is a strong inhibitor of CYP2D6.
Dalfopristin; Quinupristin: (Moderate) Concomitant use of codeine with dalfopristin; quinupristin may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of dalfopristin; quinupristin could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If dalfopristin; quinupristin is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Dalfopristin; quinupristin is a weak inhibitor of CYP3A4.
Danazol: (Moderate) Concomitant use of codeine with danazol may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of danazol could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If danazol is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Danazol is a moderate inhibitor of CYP3A4.
Dantrolene: (Major) Concomitant use of opioid agonists with dantrolene may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid agonists with dantrolene to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Avoid prescribing opioid cough medication in patients taking dantrolene.
Dapsone: (Moderate) Coadministration of dapsone with acetaminophen may increase the risk of developing methemoglobinemia. Advise patients to discontinue treatment and seek immediate medical attention with any signs or symptoms of methemoglobinemia.
Daridorexant: (Major) Concomitant use of opiate agonists with daridorexant may cause excessive sedation and somnolence. Limit the use of opiates with daridorexant to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression. Avoid prescribing cough medicines that contain opiates in patients taking daridorexant.
Darifenacin: (Moderate) Concomitant use of codeine with darifenacin may increase codeine plasma concentrations, but decrease the plasma concentration of the active metabolite, morphine, resulting in reduced efficacy or symptoms of opioid withdrawal. Avoid this combination when codeine is being used for cough; consider alternative therapy for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage increase of codeine until stable drug effects are achieved. Discontinuation of darifenacin could decrease codeine plasma concentrations and increase morphine plasma concentrations resulting in prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If darifenacin is discontinued, monitor the patient carefully and consider reducing the codeine dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Darifenacin is a moderate inhibitor of CYP2D6. In addition, the concomitant use of these drugs together may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Darifenacin has anticholinergic actions that may produce additive effects. Both agents may also cause drowsiness or blurred vision, and patients should use care in driving or performing other hazardous tasks until the effects of the drugs are known.
Darunavir: (Moderate) Concomitant use of codeine with darunavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of darunavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If darunavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Darunavir is a strong inhibitor of CYP3A4.
Darunavir; Cobicistat: (Moderate) Concomitant use of codeine with cobicistat may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of cobicistat could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If cobicistat is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Cobicistat is a strong inhibitor of CYP3A4. (Moderate) Concomitant use of codeine with darunavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of darunavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If darunavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Darunavir is a strong inhibitor of CYP3A4.
Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide: (Moderate) Concomitant use of codeine with cobicistat may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of cobicistat could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If cobicistat is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Cobicistat is a strong inhibitor of CYP3A4. (Moderate) Concomitant use of codeine with darunavir may increase codeine plasma concentrations, resulting in greater metabolism by CYP2D6, increased morphine concentrations, and prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage reduction of codeine until stable drug effects are achieved. Discontinuation of darunavir could decrease codeine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If darunavir is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Darunavir is a strong inhibitor of CYP3A4.
Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir: (Moderate) Concomitant use of codeine with ritonavir may alter codeine plasma concentrations, resulting in an unpredictable effect such as reduced efficacy or symptoms of opioid withdrawal or prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage adjustment of codeine until stable drug effects are achieved. Discontinuation of ritonavir could alter codeine plasma concentrations, resulting in an unpredictable effect such as prolonged opioid adverse reactions or decreased opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If ritonavir is discontinued, monitor the patient carefully and consider adjusting the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Ritonavir is a strong inhibitor of CYP3A4 and a weak inhibitor of CYP2D6. CYP3A4 inhibitors may increase codeine-related adverse effects while CYP2D6 inhibitors may reduce efficacy. (Moderate) Concurrent administration of acetaminophen with ritonavir may result in elevated acetaminophen plasma concentrations and subsequent adverse events. Acetaminophen is metabolized by the hepatic isoenzyme CYP3A4; ritonavir is an inhibitor of this enzyme. Caution and close monitoring are advised if these drugs are administered together.
Delavirdine: (Moderate) Concomitant use of codeine with delavirdine may alter codeine plasma concentrations, resulting in an unpredictable effect such as reduced efficacy or symptoms of opioid withdrawal or prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage adjustment of codeine until stable drug effects are achieved. Discontinuation of delavirdine could alter codeine plasma concentrations, resulting in an unpredictable effect such as prolonged opioid adverse reactions or decreased opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to codeine. If delavirdine is discontinued, monitor the patient carefully and consider adjusting the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Delavirdine is a strong inhibitor of CYP3A4 and a moderate inhibitor of CYP2D6. CYP3A4 inhibitors may increase codeine-related adverse effects while CYP2D6 inhibitors may reduce efficacy.
Desflurane: (Moderate) Concurrent use with opiate agonists can decrease the minimum alveolar concentration (MAC) of desflurane needed to produce anesthesia.
Desipramine: (Major) Concomitant use of opioid agonists with tricyclic antidepressants may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tricyclic antidepressants to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. Avoid prescribing opioid cough medication in patients taking tricyclic antidepressants.
Desmopressin: (Major) Additive hyponatremic effects may be seen in patients treated with desmopressin and drugs associated with water intoxication, hyponatremia, or SIADH including opiate agonists. Use combination with caution, and monitor patients for signs and symptoms of hyponatremia.
Desogestrel; Ethinyl Estradiol: (Moderate) Monitor for estrogen-related adverse effects during concomitant acetaminophen and ethinyl estradiol use. Acetaminophen may increase plasma ethinyl estradiol concentrations, possibly by inhibition of conjugation.
Desvenlafaxine: (Moderate) Careful monitoring, particularly during treatment initiation and dose adjustment, is recommended during coadministration of codeine and desvenlafaxine because of the potential risk of serotonin syndrome and decreased codeine efficacy. Discontinue codeine if serotonin syndrome is suspected. Additionally, concomitant use of codeine with desvenlafaxine may decrease codeine plasma concentrations resulting in reduced efficacy or symptoms of opioid withdrawal. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage increase of codeine until stable drug effects are achieved. Discontinuation of desvenlafaxine could decrease codeine plasma concentrations and increase morphine plasma concentrations resulting in prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If desvenlafaxine is discontinued, monitor the patient carefully and consider increasing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Desvenlafaxine is a weak inhibitor of CYP2D6.
Deutetrabenazine: (Major) Concomitant use of opiate agonists with deutetrabenazine may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with deutetrabenazine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking deutetrabenazine, use a lower initial dose of the opiate and titrate to clinical response. If deutetrabenazine is prescribed for a patient taking an opiate agonist, use a lower initial dose of deutetrabenazine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Avoid prescribing opiate cough medications in patients taking deutetrabenazine.
Dexamethasone: (Moderate) Concomitant use of codeine with dexamethasone can decrease codeine levels, resulting in less metabolism by CYP2D6 and decreased morphine concentrations; this may result in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor for reduced efficacy of codeine and signs of opioid withdrawal; consider increasing the dose of codeine as needed. If dexamethasone is discontinued, consider a dose reduction of codeine and frequently monitor for signs or respiratory depression and sedation. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Dexamethasone is a moderate CYP3A4 inducer.
Dexbrompheniramine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Dexbrompheniramine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Dexchlorpheniramine: (Moderate) Concomitant use of opioid agonists with dexchlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexchlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Concomitant use of opioid agonists with dexchlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexchlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Dexmedetomidine: (Moderate) Concomitant use of opioid agonists with dexmedetomidine may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medication with dexmedetomidine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Dexpanthenol: (Moderate) Use caution when using dexpanthenol with drugs that decrease gastrointestinal motility, such as opiate agonists, as it may decrease the effectiveness of dexpanthenol.
Dextroamphetamine: (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Dextromethorphan: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Dextromethorphan; Bupropion: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. (Moderate) Concomitant use of codeine with bupropion may increase codeine plasma concentrations, but decrease the plasma concentration of the active metabolite, morphine, resulting in reduced efficacy or symptoms of opioid withdrawal. It is recommended to avoid this combination when codeine is being used for cough. If coadministration is necessary, monitor patients closely at frequent intervals and consider a dosage increase of codeine until stable drug effects are achieved. Discontinuation of bupropion could decrease codeine plasma concentrations and increase morphine plasma concentrations resulting in prolonged opioid adverse reactions, including hypotension, respiratory depression, profound sedation, coma, and death. If bupropion is discontinued, monitor the patient carefully and consider reducing the opioid dosage if appropriate. Codeine is primarily metabolized by CYP2D6 to morphine, and by CYP3A4 to norcodeine; norcodeine does not have analgesic properties. Bupropion is a strong inhibitor of CYP2D6.
Dextromethorphan; Diphenhydramine; Phenylephrine: (Major) Reserve concomitant use of opioids and diphenhydramine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus. (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Dextromethorphan; Guaifenesin: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering codeine with dextromethorphan. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Dextromethorphan; Guaif