CLASSES

Estrogen with Progestogen Combinations, Excluding Hormonal Contraceptives
Monophasic Contraceptives

BOXED WARNING

Combined hormonal oral contraceptives (COCs) and estrogen-containing hormonal replacement therapy (HRT) products are contraindicated in patients with a current or past history of stroke, cerebrovascular disease, coronary artery disease, coronary thrombosis, myocardial infarction, thrombophlebitis, thromboembolism or thromboembolic disease, or valvular heart disease with complications. Hormonal COCs and estrogen-containing HRT have been associated with thromboembolism such as deep venous thrombosis (DVT) and pulmonary embolism (PE). COCs and estrogen-containing HRT are also generally contraindicated in women who have thrombogenic valvular or thrombogenic rhythm diseases of the heart (e.g., subacute bacterial endocarditis with valvular disease, or atrial fibrillation), or known inherited or acquired hypercoagulopathies (e.g., protein S deficiency, protein C deficiency, Factor V Leiden, prothrombin G20210A mutation, antithrombin deficiency, antiphospholipid antibodies). COMBINED ORAL HORMONAL CONTRACEPTIVES: COCs have been associated with thromboembolism such as deep venous thrombosis (DVT). Should a thromboembolic event occur or be suspected, the COC should be discontinued immediately. Because tobacco smoking increases the risk of thromboembolism, DVT, myocardial infarction, stroke and other thromboembolic disease, patients receiving COCs are strongly advised not to smoke. Risk is especially high for female smokers more than 35 years of age or those who smoke 15 or more cigarettes per day. Therefore, COCs are generally considered contraindicated in women over the age of 35 years who are tobacco smokers. A positive relationship between estrogen dosage and thromboembolic disease has been demonstrated, and oral products containing 50-mcg ethinyl estradiol should not be used unless medically indicated. In addition, certain progestins may increase thromboembolic risk. The overall risk of venous thromboembolism in women using COCs has been estimated to be 3 to 9 per 10,000 woman-years. Preliminary data from a large, prospective cohort safety study suggests that the risk is greatest during the first 6 months after initially starting COC therapy or restarting (following a break from therapy 4 weeks or more) with the same or different combination product. The risk of arterial thromboses, such as stroke and myocardial infarction, is especially increased in women with other risk factors for these events. Pre-existing high blood pressure, kidney disease, hypercholesterolemia, diabetes with vascular disease, and patients who are morbidly obese may also increase risk. After a COC is discontinued, the risk of thromboembolic disease due to COCs gradually disappears. Because of their association with elevations in blood pressure, COCs should be used cautiously in patients with mild to moderate hypertension or kidney disease; use is contraindicated in patients with uncontrolled or severe hypertension or hypertension with vascular disease. An increase in blood pressure has been reported in women taking COCs, and this increase is more likely in older women and with extended duration of use. The incidence of hypertension increases with increasing concentration of progestin. Blood pressure should be monitored closely in individuals with high blood pressure; discontinue the COC if blood pressure rises significantly. COCs may also cause fluid retention, and patients predisposed to complications from edema, such as those with cardiac disease or renal disease, should be closely monitored. HORMONE REPLACEMENT THERAPY (HRT): An increased risk of thromboembolism, such as pulmonary embolism (PE), DVT, as well as cardiovascular events, such as stroke and myocardial infarction (MI) has been reported with estrogen plus progestin hormone replacement therapy (HRT) in postmenopausal women. Should any of these events occur or be suspected, discontinue HRT immediately. Estrogens with or without progestins should not be used for the prevention of cardiac disease or cardiovascular disease (e.g., coronary artery disease). Patients with certain risk factors for arterial vascular disease (e.g., hypertension, diabetes, tobacco smoking, hypercholesterolemia, and morbidly obese) and/or venous thromboembolism (VTE) [e.g., personal history or family history of VTE, obese or systemic lupus (SLE)] should be monitored and managed appropriately during HRT use. In the WHI estrogen plus progestin substudy, a statistically significant 2-fold greater rate of VTE was reported in women receiving estrogen plus progestin HRT compared to women receiving placebo (35 vs. 17 per 10,000 women-years). Statistically significant increases in risk for both DVT (26 vs. 13 per 10,000 women-years) and PE (18 vs. 8 per 10,000 women-years) were also demonstrated. The increase in VTE risk was demonstrated during the first year and persisted.  In the Women's Health Initiative (WHI) estrogen-alone substudy, no overall effect on coronary heart disease (CHD) events (defined as non-fatal MI, silent MI, or CHD death) was reported in women receiving estrogen-alone compared to placebo. Subgroup analyses of women 50 to 59 years of age suggest a statistically non-significant reduction in CHD events (CE-alone vs. placebo) in women with less than 10 years since menopause (8 vs. 16 per 10,000 women-years). In the WHI estrogen plus progestin substudy, there was a statistically non-significant increased risk of CHD events reported in women receiving daily estrogen plus progestin compared to women receiving placebo (41 vs. 34 per 10,000 women-years). An increase in relative risk was demonstrated in year 1, and a trend toward decreasing relative risk was reported in years 2 through 5. Studies have also shown no cardiovascular benefit to the use of estrogens or estrogen-progestin therapy for secondary prevention in women with documented cardiac disease or CHD. Estrogens also increase the risk for stroke. In the WHI estrogen-alone substudy, a statistically significant increased risk of stroke was reported in women 50 to 79 years of age receiving estrogen-alone compared to women in the same age group receiving placebo (45 vs. 33 per 10,000 women-years). The increase in risk was demonstrated in the first year and persisted. Subgroup analyses of women 50 to 59 years of age suggest no increased risk of stroke for those women receiving estrogen-alone versus those receiving placebo (18 vs. 21 per 10,000 women-years). In the WHI estrogen plus progestin substudy, a statistically significant increased risk of stroke was reported in women 50 to 79 years of age receiving estrogen plus progestin HRT compared to women in the same age group receiving placebo (33 vs. 25 per 10,000 women-years). The increase in risk was demonstrated after the first year and persisted. Women older than 65 years of age were at increased risk for non-fatal stroke. Patients with hypertension should be monitored closely for increases in blood pressure if HRT is administered. In a few case reports, substantial increases in blood pressure have been attributed to idiosyncratic reactions to estrogen HRT therapy. In a large, randomized, placebo controlled clinical trial, a generalized effect of estrogens on blood pressure was not seen. Estrogen-based HRT may cause some degree of fluid retention. Women with conditions that might be influenced by this factor, such as a cardiac disease, warrant careful observation when estrogens are prescribed.

Norethindrone acetate; ethinyl estradiol products, including combined hormonal oral contraceptives (COCs) and hormone replacement therapy (HRT), are contraindicated in patients with a history of, or known or suspected breast cancer, as breast cancer is a hormonally-sensitive tumor. COMBINED HORMONAL CONTRACEPTION: Epidemiology studies have not found a consistent association between use of COCs and breast cancer risk. Studies do not show an association between ever (current or past) use of COCs and risk of breast cancer. However, some studies report a small increase in the risk of breast cancer among current or recent users (less than 6 months since last use) and current users with longer duration of COC use. Several large, well-designed observational studies have provided data regarding the risk of breast cancer with combined oral contraceptive (COC) use. From one large study published in 2017, the risk of breast cancer was higher among women who currently or recently used contemporary hormonal contraceptives than among women who had never used hormonal contraceptives, and this risk increased with longer durations of use; however, absolute increases in risk were small. The absolute risk of breast cancer associated with any hormonal contraceptive use was 13 per 100,000 women-years, which corresponds to 1 extra case of breast cancer for every 7,690 COC users in 1 year. Moreover, the same study data suggest that any increased risk of breast cancer usually disappears rapidly after an interruption in the use of COCs. There continues to be controversy regarding the risk of COC use in women with a family history of breast cancer (e.g., BRCA mutations). However, evidence does not suggest that the increased risk for breast cancer among women with either a family history of breast cancer or breast cancer susceptibility genes is modified by the use of COCs. All women taking COCs should receive clinical breast examinations and perform monthly self-examinations as recommended by their health care professional based on patient age, known risk factors, and current standards of care. If breast cancer is suspected in a woman who is taking hormonal contraceptives, the contraceptive should be discontinued. ESTROGEN-BASED HORMONE REPLACEMENT THERAPY (HRT): Studies suggest that the use of estrogen-progestin HRT in postmenopausal women increases the risk for invasive breast cancer (new primary malignancy). The use of estrogen-alone and estrogen plus progestin HRT has been reported to result in an increase in abnormal mammograms, requiring further evaluation. All women taking estrogen with or without a progestin as HRT should receive an annual clinical breast examination, perform monthly self-examinations, and have regular mammograms as recommended by their health care professional based on patient age, risk factors, and prior mammogram results. Since the 1970s, numerous epidemiological studies have examined the association of estrogens or combined HRT and breast cancer. The most important randomized clinical trial providing information about breast cancer in patients taking combined estrogen-progestin HRT regimens is the WHI substudy of estogen-progestin therapy. After a mean follow-up of 5.6 years, the WHI estrogen plus progestin substudy reported an increased risk of invasive breast cancer in women who took daily estogen-progestin vs. placebo. In this substudy, prior use of estrogen-alone or estrogen plus progestin therapy was reported by 26 percent of the women. The relative risk of invasive breast cancer was 1.24, and the absolute risk was 41 versus 33 cases per 10,000 women-years, for estrogen/progestin compared with placebo. Among women who reported prior use of hormone therapy, the relative risk of invasive breast cancer was 1.86, and the absolute risk was 46 vs. 25 cases per 10,000 women-years for estrogen/progestin compared with placebo. Among women who reported no prior use of hormone therapy, the relative risk of invasive breast cancer was 1.09, and the absolute risk was 40 vs. 36 cases per 10,000 women-years for estrogen/progestin compared with placebo. In the same WHI substudy, invasive breast cancers were larger, were more likely to be node positive, and were diagnosed at a more advanced stage in the combined HRT group compared with the placebo group. Metastatic disease was rare, with no apparent difference between the 2 groups. Other prognostic factors, such as histologic subtype, grade and hormone receptor status did not differ between the 2 groups. Consistent with the WHI clinical trial, observational studies have also reported an increased risk of breast cancer for estrogen plus progestin therapy, and a smaller increased risk for estrogen-alone therapy, after several years of use. The risk increased with duration of use, and appeared to return to baseline over about 5 years after stopping treatment (only the observational studies have substantial data on risk after stopping). Observational studies also suggest that the risk of breast cancer was greater, and became apparent earlier, with combined HRT as compared to estrogen-alone therapy. However, these studies have not found significant variation in the risk of breast cancer among different estrogen plus progestin combinations, doses, or routes of administration. While estrogen therapy may be used rarely for the palliative treatment of advanced breast cancer in men and women, estrogen HRT use may lead to severe hypercalcemia in patients with breast cancer and bone metastases. If hypercalcemia occurs, use of HRT should be stopped and appropriate measures taken to reduce the serum calcium level.

Hormone replacement therapy (HRT) with norethindrone acetate; ethinyl estradiol should not be used for the prevention of dementia. HRT, both estrogen-progestin combination therapy and estrogen alone therapy, has been found to fail to prevent mild cognitive impairment (memory loss) and to increase the risk of dementia in women 65 years and older. Administration of HRT should generally be avoided in women 65 years of age and older, and HRT should not be used to prevent or treat dementia or preserve cognition (memory). Overall risk vs. benefit should be considered along with the goals of use of HRT for the individual patient when considering whether to continue HRT in a geriatric woman over 65 years of age. According to the Beers Criteria, oral, topical patch, or other systemic forms of estrogens (with or without progestins), are considered potentially inappropriate medications (PIMs) for use in geriatric patients and should be avoided due to evidence of carcinogenic potential (i.e., breast and endometrium) and lack of cardiovascular or cognitive protective effects in older women. Additionally, the Beers expert panel recommends avoiding oral or transdermal estrogen in elderly women with any type of urinary incontinence due to lack of efficacy. The Beers expert panel considers use of vaginal estrogens acceptable for the management of dyspareunia, recurrent lower urinary tract infections, and other vaginal/vulvar symptoms.

DEA CLASS

Rx

DESCRIPTION

Combined oral contraceptive (COC) or hormone replacement therapy (HRT) depending on product; ethinyl estradiol is an estrogen; norethindrone acetate is a progestin of moderate androgenic and slight estrogenic activity
COC products used for routine contraception in adolescent and premenopausal females; all COCs contain a boxed warning regarding the increased risk for thromboembolism in women who smoke
HRT-oriented products used to treat symptoms of menopause or for osteoporosis prophylaxis in menopausal women; NOT effective as contraceptives; boxed warnings for HRT relate to cardiovascular, dementia, and cancer risks

COMMON BRAND NAMES

Aurovela, femhrt 1/5, Fravolv, Fyavolv, Gildess, Hailey 1.5/30, Jevantique, Jinteli 1/5, Junel 1.5/30, Junel 1/20, LARIN, Loestrin 1.5/30, Loestrin 1/20, Microgestin 1.5/30, Microgestin 1/20

HOW SUPPLIED

Aurovela/Ethinyl Estradiol, Norethindrone/femhrt 1/5/Fravolv/Fyavolv/Gildess/Hailey 1.5/30/Jevantique/Jinteli 1/5/Junel 1.5/30/Junel 1/20/LARIN/Loestrin 1.5/30/Loestrin 1/20/Microgestin 1.5/30/Microgestin 1/20/Norethindrone Acetate, Ethinyl Estradiol Oral Tab: 0.5-2.5mcg, 1-0.02mg, 1-5mcg, 1.5-0.03mg

DOSAGE & INDICATIONS

†Indicates off-label use

MAXIMUM DOSAGE

1 tablet (5 mcg estradiol with 1 mg norethindrone max dose)/day PO for menopausal symptoms or osteoporosis prevention. For oral contraception, 1 tablet/day PO as per product prescribed.

1 tablet (5 mcg estradiol with 1 mg norethindrone max dose)/day PO for menopausal symptoms or osteoporosis prevention.

For oral contraception, 1 tablet/day PO as per product prescribed.

Not indicated in prepubescent females.

DOSING CONSIDERATIONS

Contraindicated for use in patients with known liver impairment or disease.

These products have not been studied in subjects with renal impairment.

ADMINISTRATION

Hazardous Drugs Classification
NIOSH 2016 List: Group 2
NIOSH (Draft) 2020 List: Table 1
Observe and exercise appropriate precautions for handling, preparation, administration, and disposal of hazardous drugs.
Use gloves to handle. Cutting, crushing, or otherwise manipulating tablets/capsules will increase exposure and require additional protective equipment. Eye/face and respiratory protection may be needed during preparation and administration.

STORAGE

Aurovela:
- Store at controlled room temperature (between 68 and 77 degrees F)
femhrt 1/5:
- Store at 77 degrees F; excursions permitted to 59-86 degrees F
Fravolv:
- Store at 77 degrees F; excursions permitted to 59-86 degrees F
Fyavolv:
- Store at 77 degrees F; excursions permitted to 59-86 degrees F
Gildess:
- Store at controlled room temperature (between 68 and 77 degrees F)
Hailey 1.5/30:
- Store at controlled room temperature (between 68 and 77 degrees F)
Jevantique:
- Store at 77 degrees F; excursions permitted to 59-86 degrees F
Jinteli 1/5:
- Store at 77 degrees F; excursions permitted to 59-86 degrees F
Junel 1.5/30:
- Store at controlled room temperature (between 68 and 77 degrees F)
Junel 1/20:
- Store at controlled room temperature (between 68 and 77 degrees F)
LARIN:
- Store at controlled room temperature (between 68 and 77 degrees F)
Loestrin 1.5/30:
- Store at controlled room temperature (between 68 and 77 degrees F)
Loestrin 1/20:
- Store at controlled room temperature (between 68 and 77 degrees F)
Microgestin 1.5/30:
- Store at controlled room temperature (between 68 and 77 degrees F)
Microgestin 1/20:
- Store at controlled room temperature (between 68 and 77 degrees F)

CONTRAINDICATIONS / PRECAUTIONS

Use of norethindrone acetate; ethinyl estradiol, as with other contraceptive and hormone replacement steroids, may result in clinical changes that influence the results of certain laboratory tests, such as coagulation factors, lipids, glucose tolerance, and binding proteins. Specific laboratory test interference has not been reported.

Norethindrone acetate; ethinyl estradiol combined hormonal oral contraceptive (COC) products do not protect against human immunodeficiency virus (HIV) infection or other sexually transmitted disease. Patients with known HIV infection or acquired immunodeficiency syndrome (AIDS) should be aware that COC use will not prevent the transmission of HIV or other diseases to their partner(s).

Combined hormonal oral contraceptives (COCs) and estrogen-containing hormonal replacement therapy (HRT) products are contraindicated in patients with a current or past history of stroke, cerebrovascular disease, coronary artery disease, coronary thrombosis, myocardial infarction, thrombophlebitis, thromboembolism or thromboembolic disease, or valvular heart disease with complications. Hormonal COCs and estrogen-containing HRT have been associated with thromboembolism such as deep venous thrombosis (DVT) and pulmonary embolism (PE). COCs and estrogen-containing HRT are also generally contraindicated in women who have thrombogenic valvular or thrombogenic rhythm diseases of the heart (e.g., subacute bacterial endocarditis with valvular disease, or atrial fibrillation), or known inherited or acquired hypercoagulopathies (e.g., protein S deficiency, protein C deficiency, Factor V Leiden, prothrombin G20210A mutation, antithrombin deficiency, antiphospholipid antibodies). COMBINED ORAL HORMONAL CONTRACEPTIVES: COCs have been associated with thromboembolism such as deep venous thrombosis (DVT). Should a thromboembolic event occur or be suspected, the COC should be discontinued immediately. Because tobacco smoking increases the risk of thromboembolism, DVT, myocardial infarction, stroke and other thromboembolic disease, patients receiving COCs are strongly advised not to smoke. Risk is especially high for female smokers more than 35 years of age or those who smoke 15 or more cigarettes per day. Therefore, COCs are generally considered contraindicated in women over the age of 35 years who are tobacco smokers. A positive relationship between estrogen dosage and thromboembolic disease has been demonstrated, and oral products containing 50-mcg ethinyl estradiol should not be used unless medically indicated. In addition, certain progestins may increase thromboembolic risk. The overall risk of venous thromboembolism in women using COCs has been estimated to be 3 to 9 per 10,000 woman-years. Preliminary data from a large, prospective cohort safety study suggests that the risk is greatest during the first 6 months after initially starting COC therapy or restarting (following a break from therapy 4 weeks or more) with the same or different combination product. The risk of arterial thromboses, such as stroke and myocardial infarction, is especially increased in women with other risk factors for these events. Pre-existing high blood pressure, kidney disease, hypercholesterolemia, diabetes with vascular disease, and patients who are morbidly obese may also increase risk. After a COC is discontinued, the risk of thromboembolic disease due to COCs gradually disappears. Because of their association with elevations in blood pressure, COCs should be used cautiously in patients with mild to moderate hypertension or kidney disease; use is contraindicated in patients with uncontrolled or severe hypertension or hypertension with vascular disease. An increase in blood pressure has been reported in women taking COCs, and this increase is more likely in older women and with extended duration of use. The incidence of hypertension increases with increasing concentration of progestin. Blood pressure should be monitored closely in individuals with high blood pressure; discontinue the COC if blood pressure rises significantly. COCs may also cause fluid retention, and patients predisposed to complications from edema, such as those with cardiac disease or renal disease, should be closely monitored. HORMONE REPLACEMENT THERAPY (HRT): An increased risk of thromboembolism, such as pulmonary embolism (PE), DVT, as well as cardiovascular events, such as stroke and myocardial infarction (MI) has been reported with estrogen plus progestin hormone replacement therapy (HRT) in postmenopausal women. Should any of these events occur or be suspected, discontinue HRT immediately. Estrogens with or without progestins should not be used for the prevention of cardiac disease or cardiovascular disease (e.g., coronary artery disease). Patients with certain risk factors for arterial vascular disease (e.g., hypertension, diabetes, tobacco smoking, hypercholesterolemia, and morbidly obese) and/or venous thromboembolism (VTE) [e.g., personal history or family history of VTE, obese or systemic lupus (SLE)] should be monitored and managed appropriately during HRT use. In the WHI estrogen plus progestin substudy, a statistically significant 2-fold greater rate of VTE was reported in women receiving estrogen plus progestin HRT compared to women receiving placebo (35 vs. 17 per 10,000 women-years). Statistically significant increases in risk for both DVT (26 vs. 13 per 10,000 women-years) and PE (18 vs. 8 per 10,000 women-years) were also demonstrated. The increase in VTE risk was demonstrated during the first year and persisted.  In the Women's Health Initiative (WHI) estrogen-alone substudy, no overall effect on coronary heart disease (CHD) events (defined as non-fatal MI, silent MI, or CHD death) was reported in women receiving estrogen-alone compared to placebo. Subgroup analyses of women 50 to 59 years of age suggest a statistically non-significant reduction in CHD events (CE-alone vs. placebo) in women with less than 10 years since menopause (8 vs. 16 per 10,000 women-years). In the WHI estrogen plus progestin substudy, there was a statistically non-significant increased risk of CHD events reported in women receiving daily estrogen plus progestin compared to women receiving placebo (41 vs. 34 per 10,000 women-years). An increase in relative risk was demonstrated in year 1, and a trend toward decreasing relative risk was reported in years 2 through 5. Studies have also shown no cardiovascular benefit to the use of estrogens or estrogen-progestin therapy for secondary prevention in women with documented cardiac disease or CHD. Estrogens also increase the risk for stroke. In the WHI estrogen-alone substudy, a statistically significant increased risk of stroke was reported in women 50 to 79 years of age receiving estrogen-alone compared to women in the same age group receiving placebo (45 vs. 33 per 10,000 women-years). The increase in risk was demonstrated in the first year and persisted. Subgroup analyses of women 50 to 59 years of age suggest no increased risk of stroke for those women receiving estrogen-alone versus those receiving placebo (18 vs. 21 per 10,000 women-years). In the WHI estrogen plus progestin substudy, a statistically significant increased risk of stroke was reported in women 50 to 79 years of age receiving estrogen plus progestin HRT compared to women in the same age group receiving placebo (33 vs. 25 per 10,000 women-years). The increase in risk was demonstrated after the first year and persisted. Women older than 65 years of age were at increased risk for non-fatal stroke. Patients with hypertension should be monitored closely for increases in blood pressure if HRT is administered. In a few case reports, substantial increases in blood pressure have been attributed to idiosyncratic reactions to estrogen HRT therapy. In a large, randomized, placebo controlled clinical trial, a generalized effect of estrogens on blood pressure was not seen. Estrogen-based HRT may cause some degree of fluid retention. Women with conditions that might be influenced by this factor, such as a cardiac disease, warrant careful observation when estrogens are prescribed.

Surgery can increase the risk for thromboembolism from combined hormonal contraceptives(COCs) and estrogen-based hormone replacement therapy (HRT). If feasible, discontinue norethindrone acetate; ethinyl estradiol products at least 4 weeks before and through 2 weeks after major surgery or other surgeries known to have an elevated risk of thromboembolism, and during and following any prolonged immobilization. The decision on when to resume COCs or HRT after such procedures or conditions would be based on the perceived additional thromboembolic risk; resume only after the patient is fully ambulatory. In addition, advise treated patients to move about periodically during travel involving prolonged immobilization.

Because of the increased potential for embolic risk, combined oral contraceptives (COCs) containing ethinyl estradiol; norethindrone acetate are contraindicated in women who currently have diabetes mellitus and are over 35 years of age, diabetes mellitus with hypertension or with vascular disease or end-organ damage, or diabetes mellitus of greater than 20 years duration. Patients with diabetes mellitus should be observed for changes in glucose tolerance when initiating or discontinuing estrogen therapy with COC or as hormone replacement therapy (HRT), since estrogen therapy may exacerbate diabetes. Altered glucose tolerance secondary to decreased insulin sensitivity has been reported.

Women who are being treated for dyslipidemia should be followed closely if they elect to use combined hormonal oral contraceptives (COCs) or hormone replacement therapy (HRT). Some progestogens may elevate LDL levels and may render the control of hyperlipidemia more difficult. Females with hypertriglyceridemia, or a family history thereof, may be at an increased risk of pancreatitis when using COCs. Consider discontinuation of treatment if pancreatitis occurs. 

Ethinyl estradiol; norethindrone acetate combined hormonal oral contraceptive (COC) products are contraindicated in patients with migraine or other headache that is accompanied by focal neurological symptoms, such as aura, or women over age 35 with any migraine headaches. COCs may cause an exacerbation of migraine or a change in headache patterns and should be used with caution in women with migraine. Patients who complain of migraine with focal neurologic visual changes should be medically evaluated, and in some patients, such changes may indicate cerebrovascular events. Similarly to COC products, estrogen-based hormone replacement therapy (HRT) may cause an exacerbation of migraine, and should be used with caution in women with these conditions.

Consistent with potential thrombotic effects of combined oral hormonal contraceptives (COCs) and estrogen-based hormone replacement therapy (HRT), there have been clinical case reports of retinal thrombosis with use. Discontinue treatment if there is unexplained visual disturbance, partial or complete loss of vision, onset of proptosis or diplopia, papilledema, or retinal vascular lesions. Appropriate diagnostic and therapeutic measures should be undertaken immediately. Estrogens can increase the curvature of the cornea; patients using contact lenses wearers who develop visual changes or changes in lens tolerance should be assessed by an ophthalmologist.

Do not use norethindrone acetate; ethinyl estradiol products in patients with a known hypersensitivity to any of the specific product ingredients; ethinyl estradiol is contraindicated in patients with known anaphylactic reactions or history of angioedema to the drug. Cases of both anaphylactic reactions and angioedema have been reported in patients taking estrogens. Events have developed in minutes and have required emergency medical treatment. Exogenous estrogens may also induce or exacerbate symptoms of angioedema, particularly in women with hereditary angioedema, which can be hormonally sensitive.

Given the increased prevalence of hypercoagulable states in patients with systemic lupus erythematosus (SLE) (in particular antiphospholipid antibodies and lupus anticoagulant) and the risk factors for thromboembolism, consider risks vs. benefit of COC or estrogen-based HRT use in these patients. Avoid COC or estrogen-based HRT use in SLE patients with a history of venous or arterial thrombosis or the presence of a hypercoagulable state. If COCs are initiated in SLE patients without hypercoagulable states, choose a low-dose estrogen contraceptive (e.g., ethinyl estradiol 35 mcg per day or less); consider use of a progestin-only contraceptive. Combined hormonal oral contraceptive (COC) or estrogen-based hormone replacement therapy (HRT) use has also been reported to induce, unmask, or exacerbate SLE; more data are needed. 

Discontinue norethindrone acetate; ethinyl estradiol products if pregnancy is detected; there is no reason to continue combined oral hormonal contraceptives (COCs) during pregnancy. Estrogen-based hormone replacement therapy (HRT) should not be used during pregnancy. Epidemiologic studies and meta-analyses have not found an increased risk of genital or nongenital birth defects (including cardiac anomalies and limb-reduction defects) following exposure to COCs before conception or during early pregnancy. For any patient who has missed two consecutive periods, pregnancy should be ruled out. If the patient has not adhered to the prescribed COC schedule, consider the possibility of pregnancy at the first missed period. Discontinue COC use if pregnancy is confirmed.

Estrogen-based hormone replacement therapy (HRT) should not be used during lactation. Manufacturers recommend avoidance of combined hormonal oral contraceptives (COCs) if possible until a mother has completely weaned her child. Small amounts of oral contraceptive steroids (estrogens and progestins) have been identified in the milk of nursing mothers and a few reports of effects on the infant exist, including jaundice and breast enlargement. Experts often recommend avoidance of estrogen-containing hormonal contraceptives, in the first 21 days postpartum due to maternal post-partum risks for thromboembolism following obstetric delivery, and the potential for COCs to interfere with the establishment of lactation. It is generally accepted that estrogen-containing combined hormonal contraceptives may be used after this period in healthy women without other risk factors; general monitoring of the infant for effects such as appetite changes, breast changes and proper weight gain and growth should occur. Estrogens, including ethinyl estradiol (EE), have been reported to interfere with milk production and duration of lactation in some women, particularly at doses of 30 mcg per day or more. One study found that lower dose oral combined contraceptives (e.g., 10 mcg per day EE) may not affect lactation. However, a systematic review concluded that the available evidence, even from randomized controlled trials, is limited and of poor quality; proper trials are needed. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition. Alternate contraceptive agents for consideration for use during breast-feeding include non-hormonal contraceptive methods and also progestin-only contraceptives (e.g., medroxyprogesterone injection).

LIVER/GI SYSTEM ISSUES with COMBINED HORMONAL ORAL CONTRACEPTIVES: Combined oral contraceptives (COCs) are contraindicated in patients with hepatic disease. Because of the association with cholestasis and hepatic neoplasms, estrogens are contraindicated in the presence of hepatocellular cancer, hepatic adenoma, other liver tumors (benign or malignant), or markedly impaired liver function (e.g., uncompensated cirrhosis). Do not use COCs in patients with a history of cholestatic jaundice/pruritus of pregnancy or jaundice from prior hormonal contraceptives; these conditions can recur with subsequent COC use. Discontinue use of the COC if jaundice develops during combined oral contraceptive use. Steroid hormones may be poorly metabolized in patients with liver impairment. Acute or chronic disturbances of liver function may necessitate the discontinuation of COC use until markers of liver function return to normal and COC causation has been excluded. Patients with hepatitis C who are being treated with ombitasvir/paritaprevir/ritonavir, with or without dasabuvir are also contraindicated to receive COCs. During clinical trials with the hepatitis C combination drug regimen that contains ombitasvir/paritaprevir/ritonavir, with or without dasabuvir, ALT elevations greater than 5 times the upper limit of normal (ULN), including some cases greater than 20 times the ULN, were significantly more frequent in women using ethinyl estradiol-containing medications. Discontinue COCs before starting hepatitis C therapy with the combination drug regimen ombitasvir/paritaprevir/ritonavir, with or without dasabuvir; a COC can be restarted approximately 2 weeks following completion of treatment with the hepatitis C combination drug regimen. Hepatic adenomas are associated with COC use. An estimate of the attributable risk is 3.3 cases/100,000 COC users. Rupture of hepatic adenomas may cause death through intra-abdominal hemorrhage. Studies have shown an increased risk of developing hepatocellular carcinoma in long term (more than 8 years) COC users. However, the attributable risk of liver cancers in COC users is less than 1 case per million users. Use COCs with caution in patients with pre-existing gallbladder disease; however, recent studies have shown that the relative risk of developing gallbladder disease among COC users appears minimal due to the use of products that contain lower doses of hormones. LIVER/GI SYSTEM ISSUES with ESTROGEN-BASED HRT POSTMENOPAUSE: Ethinyl estradiol; norethindrone acetate HRT products are contraindicated in the presence of hepatocellular cancer, hepatic adenoma, or in severe hepatic disease of any type. Estrogens and progestins may be poorly metabolized in women with impaired liver function. For women with a history of cholestatic jaundice associated with past estrogen use or with pregnancy, caution should be exercised, and in the case of recurrence, estrogens should be discontinued. Estrogens should also be used cautiously in patients with acute intermittent, or variegate hepatic porphyria, which can be exacerbated. Estrogens have been reported during trials to increase the risk of gallbladder disease (e.g., cholestasis, cholelithiasis and cholecystitis) by roughly 2- to 4-fold in postmenopausal women; use with caution in patients with a history of gallbladder disease.

Mood disorders, like depression, may be aggravated in women taking combined oral hormonal contraceptives (COCs). Data regarding the association of COCs with onset of depression or exacerbation of existing depression are limited. If significant depression occurs, norethindrone acetate; ethinyl estradiol products should be discontinued. Mood disorders, like depression, may be aggravated in women taking estrogen-based hormone replacement therapy (HRT); if significant depression occurs, the HRT should be discontinued.

Norethindrone acetate; ethinyl estradiol products, including combined hormonal oral contraceptives (COCs) and hormone replacement therapy (HRT), are contraindicated in patients with a history of, or known or suspected breast cancer, as breast cancer is a hormonally-sensitive tumor. COMBINED HORMONAL CONTRACEPTION: Epidemiology studies have not found a consistent association between use of COCs and breast cancer risk. Studies do not show an association between ever (current or past) use of COCs and risk of breast cancer. However, some studies report a small increase in the risk of breast cancer among current or recent users (less than 6 months since last use) and current users with longer duration of COC use. Several large, well-designed observational studies have provided data regarding the risk of breast cancer with combined oral contraceptive (COC) use. From one large study published in 2017, the risk of breast cancer was higher among women who currently or recently used contemporary hormonal contraceptives than among women who had never used hormonal contraceptives, and this risk increased with longer durations of use; however, absolute increases in risk were small. The absolute risk of breast cancer associated with any hormonal contraceptive use was 13 per 100,000 women-years, which corresponds to 1 extra case of breast cancer for every 7,690 COC users in 1 year. Moreover, the same study data suggest that any increased risk of breast cancer usually disappears rapidly after an interruption in the use of COCs. There continues to be controversy regarding the risk of COC use in women with a family history of breast cancer (e.g., BRCA mutations). However, evidence does not suggest that the increased risk for breast cancer among women with either a family history of breast cancer or breast cancer susceptibility genes is modified by the use of COCs. All women taking COCs should receive clinical breast examinations and perform monthly self-examinations as recommended by their health care professional based on patient age, known risk factors, and current standards of care. If breast cancer is suspected in a woman who is taking hormonal contraceptives, the contraceptive should be discontinued. ESTROGEN-BASED HORMONE REPLACEMENT THERAPY (HRT): Studies suggest that the use of estrogen-progestin HRT in postmenopausal women increases the risk for invasive breast cancer (new primary malignancy). The use of estrogen-alone and estrogen plus progestin HRT has been reported to result in an increase in abnormal mammograms, requiring further evaluation. All women taking estrogen with or without a progestin as HRT should receive an annual clinical breast examination, perform monthly self-examinations, and have regular mammograms as recommended by their health care professional based on patient age, risk factors, and prior mammogram results. Since the 1970s, numerous epidemiological studies have examined the association of estrogens or combined HRT and breast cancer. The most important randomized clinical trial providing information about breast cancer in patients taking combined estrogen-progestin HRT regimens is the WHI substudy of estogen-progestin therapy. After a mean follow-up of 5.6 years, the WHI estrogen plus progestin substudy reported an increased risk of invasive breast cancer in women who took daily estogen-progestin vs. placebo. In this substudy, prior use of estrogen-alone or estrogen plus progestin therapy was reported by 26 percent of the women. The relative risk of invasive breast cancer was 1.24, and the absolute risk was 41 versus 33 cases per 10,000 women-years, for estrogen/progestin compared with placebo. Among women who reported prior use of hormone therapy, the relative risk of invasive breast cancer was 1.86, and the absolute risk was 46 vs. 25 cases per 10,000 women-years for estrogen/progestin compared with placebo. Among women who reported no prior use of hormone therapy, the relative risk of invasive breast cancer was 1.09, and the absolute risk was 40 vs. 36 cases per 10,000 women-years for estrogen/progestin compared with placebo. In the same WHI substudy, invasive breast cancers were larger, were more likely to be node positive, and were diagnosed at a more advanced stage in the combined HRT group compared with the placebo group. Metastatic disease was rare, with no apparent difference between the 2 groups. Other prognostic factors, such as histologic subtype, grade and hormone receptor status did not differ between the 2 groups. Consistent with the WHI clinical trial, observational studies have also reported an increased risk of breast cancer for estrogen plus progestin therapy, and a smaller increased risk for estrogen-alone therapy, after several years of use. The risk increased with duration of use, and appeared to return to baseline over about 5 years after stopping treatment (only the observational studies have substantial data on risk after stopping). Observational studies also suggest that the risk of breast cancer was greater, and became apparent earlier, with combined HRT as compared to estrogen-alone therapy. However, these studies have not found significant variation in the risk of breast cancer among different estrogen plus progestin combinations, doses, or routes of administration. While estrogen therapy may be used rarely for the palliative treatment of advanced breast cancer in men and women, estrogen HRT use may lead to severe hypercalcemia in patients with breast cancer and bone metastases. If hypercalcemia occurs, use of HRT should be stopped and appropriate measures taken to reduce the serum calcium level.

Estrogen-based hormone regimens are contraindicated in the presence of cervical cancer or other estrogen-responsive tumors. COMBINED HORMONAL ORAL CONTRACEPTIVES (COCs): Most cervical cancers are related to the presence of the human papillomavirus (HPV), but hormonal factors influence risk. In women taking COCs, studies have found an increased risk of cervical cancer compared with never-users. The risk appears to increase with duration of use and appears to decline when COCs are discontinued. Clinical surveillance of all women using COCs is important; all women receiving COC treatment should have a pelvic examination and other diagnostic or screening tests, such as cervical cytology, as clinically indicated or as generally recommended based on age, risk factors, and other individual needs. ESTROGEN-BASED HORMONE REPLACEMENT THERAPY: An increased risk for cervical dysplasia or cancer has NOT been noted with the use of estrogen-progestin hormone replacement therapy (HRT) postmenopause. Because estrogens influence the growth of endometrial tissues, use estradiol or other estrogens cautiously in women with endometriosis or uterine leiomyomata (uterine fibroids). A few cases of malignant transformation of residual endometrial growths have been reported in women treated post-hysterectomy with estrogen-alone therapy. For women known to have residual endometriosis post-hysterectomy, consider the addition of a progestin to estrogen therapy, such as the use of estradiol; norethindrone products, to reduce the risk of endometrial tissue growth. Clinical surveillance of all women using estrogen-alone or estrogen plus progestin HRT is important; all women receiving estrogen treatment should have a pelvic examination and other diagnostic or screening tests, such as cervical cytology, as clinically indicated or as generally recommended based on age, risk factors, and other individual needs.

Norethindrone acetate; ethinyl estradiol combined oral contraceptive (COC) and hormonal replacement therapy (HRT) products are contraindicated in women with estrogen-dependent neoplasms, including ovarian cancer. ORAL CONTRACEPTIVES: Many studies have documented a protective effect of COCs against ovarian cancer, with the protective effects increasing with duration of use; the protective effects appear to persist for 15 years or more after stopping COC use.   HORMONE REPLACEMENT THERAPY (HRT): The use of HRT increases ovarian cancer risk in peri- and postmenopausal women. What is known about the risk of ovarian cancer due to HRT is derived from data available for estrogen-alone and estrogen plus progestin products. The Women's Health Initiative (WHI) estrogen plus progestin substudy reported a statistically non-significant increased risk of ovarian cancer. After an average follow-up of 5.6 years, the relative risk for ovarian cancer for estrogen plus progestin versus placebo was 1.58 (95% CI 0.77 to 3.24). The absolute risk for estrogen plus progestin versus placebo was 4 versus 3 cases per 10,000 women-years. A meta-analysis of 17 prospective and 35 retrospective epidemiology studies found that women who used hormonal therapy for menopausal symptoms had an increased risk for ovarian cancer. The primary analysis, using case-control comparisons, included 12,110 cancer cases from the 17 prospective studies. The relative risk associated with current use of hormonal therapy was 1.41 (95% confidence interval [CI] 1.32 to 1.5); there was no difference in the risk estimates by duration of the exposure (less than 5 years [median of 3 years] vs. greater than 5 years [median of 10 years] of use before the cancer diagnosis). The relative risk associated with combined current and recent use (discontinued use within 5 years before cancer diagnosis) was 1.37 (95% CI 1.27 to 1.48), and the elevated risk was significant for both estrogen-alone and estrogen plus progestin products. The exact duration of hormone therapy use associated with an increased risk of ovarian cancer, however, is unknown.

Combined oral contraceptives (COCs) and hormone replacement therapy (HRT) are contraindicated in the presence of vaginal cancer, cervical cancer, uterine cancer, or other estrogen-responsive tumors. Clinical surveillance of all women using COCs or HRT is important; all women receiving COC or HRT treatment should have a pelvic examination and other diagnostic or screening tests, such as cervical cytology, as clinically indicated or as generally recommended based on age, risk factors, and other individual needs. Because estrogens influence the growth of endometrial tissues, use estradiol or other estrogens for HRT cautiously in women with endometriosis or uterine leiomyomata (uterine fibroids). A few cases of malignant transformation of residual endometrial growths have been reported in women treated post-hysterectomy with estrogen-alone HRT therapy. For women known to have residual endometriosis post-hysterectomy, consider the addition of a progestin to estrogen HRT, such as the use of norethindrone acetate; ethinyl estradiol products, to reduce the risk of endometrial tissue growth.

Norethindrone acetate; ethinyl estradiol products are contraindicated in patients with known estrogen-dependent malignancies, such as endometrial cancer. HORMONE REPLACEMENT THERAPY (HRT): There is an association of unopposed estrogen therapy and endometrial cancer in women with an intact uterus. Adding a progestin to estrogen therapy has been shown to reduce, but not eliminate, the risk of endometrial hyperplasia, which may be a precursor to endometrial cancer. Clinical surveillance of all women using estrogen-alone or estrogen plus progestin therapy is important. Adequate diagnostic measures, including directed or random endometrial sampling when indicated, should be undertaken to rule out malignancy in postmenopausal women with undiagnosed persistent or recurring abnormal vaginal bleeding. The reported endometrial cancer risk among unopposed estrogen users is about 2- to 12-times greater than in non-users, and appears dependent on duration of treatment and on estrogen dose. Most studies show no significant increased risk associated with use of estrogens for less than 1 year. The greatest risk appears associated with prolonged use, with increased risks of 15-to 24-fold for 5 to 10 years or more, and this risk has been shown to persist for at least 8 to 15 years after estrogen therapy is discontinued. There is no evidence that the use of natural estrogens results in a different endometrial risk profile than synthetic estrogens of equivalent estrogen dose. With concurrent progestin use, such as choosing a combination HRT product, the incidence of endometrial hyperplasia due to estrogen therapy is estimated to be 1% or less. HORMONAL CONTRACEPTIVES: Hormonal contraceptives are contraindicated in women with undiagnosed vaginal bleeding; evaluate such patients before use and determine if a contraindication exists. Unlike HRT, the use of combined oral contraceptives (COCs) appears to have a protective effect on the endometrium. In women using COCs, a meta-analysis of 10 studies indicates a significant trend in decreasing endometrial carcinoma risk with increasing duration of COC use. The beneficial effects of COCs in this regard may persist for 15 years or more after COC use ceases. 

The estrogen component of combined oral hormonal contraceptives or HRT may raise the serum concentrations of thyroid-binding globulin, sex hormone-binding globulin, and cortisol-binding globulin. Doses of thyroid hormone replacement for hypothyroidism may need to be increased, as indicated by clinical and laboratory monitoring for the individual. Cortisol replacement therapy (e.g., corticosteroid therapy) may also need adjusted for some patients.

Chloasma may occur with combined oral hormonal contraceptive (COC) use, especially in women with a history of chloasma gravidarum (melasma). Advise females who tend to develop chloasma to avoid exposure to the sun or ultraviolet (UV) exposure while taking norethindrone acetate; ethinyl estradiol for birth control.

Preexisting morbid obesity is one factor that may increase cardiovascular or thromboembolic risks associated with combination hormonal contraceptive use. Consider the presence of obesity and other underlying risk factors that may increase the risk of cardiovascular disease or thromboembolism, particularly for women over 35 years of age. Obesity may also increase thromboembolic risks due to HRT in postmenopausal women. Limited literature suggests that the effectiveness of some hormonal contraceptive formulations might decrease with increasing body mass index (BMI). However, the evidence is conflicting; there are also data to suggest that the efficacy of most combined hormonal contraceptive products (with a few known exceptions) does not seem to be compromised in women who are overweight.

Estrogen replacement therapy, such as the use of norethindrone acetate; ethinyl estradiol as HRT for menopause or osteoporosis, should be used with caution in women with hypoparathyroidism as estrogen-induced hypocalcemia may occur.

The safety and efficacy of norethindrone acetate; ethinyl estradiol hormone replacement therapy (HRT) have not been established in pediatric patients. The safety and efficacy of hormonal contraceptive products have only been established in females of reproductive age. Safety and efficacy of hormonal birth control is expected to be the same for postpubertal children under the age of 16 and for users 16 years of age and older. Use of hormonal contraceptive products in female children before menarche is not indicated.

Hormone replacement therapy (HRT) with norethindrone acetate; ethinyl estradiol should not be used for the prevention of dementia. HRT, both estrogen-progestin combination therapy and estrogen alone therapy, has been found to fail to prevent mild cognitive impairment (memory loss) and to increase the risk of dementia in women 65 years and older. Administration of HRT should generally be avoided in women 65 years of age and older, and HRT should not be used to prevent or treat dementia or preserve cognition (memory). Overall risk vs. benefit should be considered along with the goals of use of HRT for the individual patient when considering whether to continue HRT in a geriatric woman over 65 years of age. According to the Beers Criteria, oral, topical patch, or other systemic forms of estrogens (with or without progestins), are considered potentially inappropriate medications (PIMs) for use in geriatric patients and should be avoided due to evidence of carcinogenic potential (i.e., breast and endometrium) and lack of cardiovascular or cognitive protective effects in older women. Additionally, the Beers expert panel recommends avoiding oral or transdermal estrogen in elderly women with any type of urinary incontinence due to lack of efficacy. The Beers expert panel considers use of vaginal estrogens acceptable for the management of dyspareunia, recurrent lower urinary tract infections, and other vaginal/vulvar symptoms.

ADVERSE REACTIONS

thromboembolism / Delayed / 0-1.0
intracranial bleeding / Delayed / 0-1.0
optic neuritis / Delayed / 0-1.0
papilledema / Delayed / 0-1.0
retinal thrombosis / Delayed / 0-1.0
visual impairment / Early / 0-1.0
hepatoma / Delayed / 0-1.0
pancreatitis / Delayed / 0-1.0
porphyria / Delayed / 0-1.0
myocardial infarction / Delayed / Incidence not known
pulmonary embolism / Delayed / Incidence not known
thrombosis / Delayed / Incidence not known
stroke / Early / Incidence not known
anaphylactoid reactions / Rapid / Incidence not known
erythema multiforme / Delayed / Incidence not known
erythema nodosum / Delayed / Incidence not known
angioedema / Rapid / Incidence not known
bowel ischemia / Delayed / Incidence not known
cholecystitis / Delayed / Incidence not known
dementia / Delayed / Incidence not known
lupus-like symptoms / Delayed / Incidence not known
new primary malignancy / Delayed / Incidence not known
ovarian cancer / Delayed / Incidence not known
breast cancer / Delayed / Incidence not known
endometrial cancer / Delayed / Incidence not known

candidiasis / Delayed / 2.0-6.0
vaginitis / Delayed / 2.0-6.0
depression / Delayed / 2.0-5.8
galactorrhea / Delayed / 0-1.0
cataracts / Delayed / 0-1.0
elevated hepatic enzymes / Delayed / 0-1.0
jaundice / Delayed / 0-1.0
peliosis hepatis / Delayed / 0-1.0
hepatitis / Delayed / 0-1.0
endometrial hyperplasia / Delayed / 0-1.0
lactation suppression / Early / Incidence not known
fluid retention / Delayed / Incidence not known
hypertension / Early / Incidence not known
edema / Delayed / Incidence not known
migraine / Early / Incidence not known
cholelithiasis / Delayed / Incidence not known
colitis / Delayed / Incidence not known
cholestasis / Delayed / Incidence not known
hypertriglyceridemia / Delayed / Incidence not known
hyperlipidemia / Delayed / Incidence not known
impaired cognition / Early / Incidence not known
urinary incontinence / Early / Incidence not known
cystitis / Delayed / Incidence not known
cervical dysplasia / Delayed / Incidence not known

amenorrhea / Delayed / 0-90.0
breakthrough bleeding / Delayed / 83.9-83.9
breast enlargement / Delayed / 1.0-10.0
leukorrhea / Delayed / 1.0-10.0
vaginal irritation / Early / 1.0-10.0
vaginal discharge / Delayed / 1.0-10.0
weight gain / Delayed / 1.0-10.0
irritability / Delayed / 1.0-10.0
fatigue / Early / 1.0-10.0
libido increase / Delayed / 1.0-10.0
asthenia / Delayed / 1.0-10.0
libido decrease / Delayed / 1.0-10.0
vomiting / Early / 1.0-10.0
abdominal pain / Early / 1.0-10.0
mastalgia / Delayed / 2.0-9.0
myalgia / Early / 7.8-8.6
pelvic pain / Delayed / 2.0-6.0
emotional lability / Early / 2.0-6.0
acne vulgaris / Delayed / 2.0-6.0
arthralgia / Delayed / 2.9-5.8
back pain / Delayed / 4.7-5.3
menstrual irregularity / Delayed / 5.0-5.0
menorrhagia / Delayed / 5.0-5.0
dysmenorrhea / Delayed / 4.0-4.0
anxiety / Delayed / 2.0-2.0
breast discharge / Delayed / 0-1.0
diplopia / Early / 0-1.0
headache / Early / 10.0
nausea / Early / 10.0
melasma / Delayed / Incidence not known
maculopapular rash / Early / Incidence not known
urticaria / Rapid / Incidence not known
photosensitivity / Delayed / Incidence not known
alopecia / Delayed / Incidence not known
pruritus / Rapid / Incidence not known
hirsutism / Delayed / Incidence not known
rash / Early / Incidence not known
gingivitis / Delayed / Incidence not known
anorexia / Delayed / Incidence not known
weight loss / Delayed / Incidence not known
muscle cramps / Delayed / Incidence not known
musculoskeletal pain / Early / Incidence not known
rhinitis / Early / Incidence not known
sinusitis / Delayed / Incidence not known

DRUG INTERACTIONS

Acarbose: (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
Acetaminophen: (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.
Acetaminophen; Aspirin, ASA; Caffeine: (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. (Minor) Serum concentrations of caffeine may be increased during concurrent administration with ethinyl estradiol. Patients may desire to limit products that contain high amounts of caffeine to minimize caffeine-related side effects such as nausea or tremors.
Acetaminophen; Aspirin: (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.
Acetaminophen; Aspirin; Diphenhydramine: (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.
Acetaminophen; Caffeine: (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. (Minor) Serum concentrations of caffeine may be increased during concurrent administration with ethinyl estradiol. Patients may desire to limit products that contain high amounts of caffeine to minimize caffeine-related side effects such as nausea or tremors.
Acetaminophen; Caffeine; Dihydrocodeine: (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. (Minor) Serum concentrations of caffeine may be increased during concurrent administration with ethinyl estradiol. Patients may desire to limit products that contain high amounts of caffeine to minimize caffeine-related side effects such as nausea or tremors.
Acetaminophen; Caffeine; Pyrilamine: (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. (Minor) Serum concentrations of caffeine may be increased during concurrent administration with ethinyl estradiol. Patients may desire to limit products that contain high amounts of caffeine to minimize caffeine-related side effects such as nausea or tremors.
Acetaminophen; Chlorpheniramine: (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.
Acetaminophen; Chlorpheniramine; Dextromethorphan: (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.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (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.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (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.
Acetaminophen; Chlorpheniramine; Phenylephrine : (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.
Acetaminophen; Codeine: (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.
Acetaminophen; Dextromethorphan: (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.
Acetaminophen; Dextromethorphan; Doxylamine: (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.
Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (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.
Acetaminophen; Dextromethorphan; Guaifenesin; Pseudoephedrine: (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.
Acetaminophen; Dextromethorphan; Phenylephrine: (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.
Acetaminophen; Dextromethorphan; Pseudoephedrine: (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.
Acetaminophen; Dichloralphenazone; Isometheptene: (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.
Acetaminophen; Diphenhydramine: (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.
Acetaminophen; Guaifenesin; Phenylephrine: (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.
Acetaminophen; Hydrocodone: (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.
Acetaminophen; Ibuprofen: (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.
Acetaminophen; Oxycodone: (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.
Acetaminophen; Pamabrom; Pyrilamine: (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.
Acetaminophen; Pentazocine: (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.
Acetaminophen; Pseudoephedrine: (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.
Acetohexamide: (Minor) Progestins can impair glucose tolerance. Patients receiving antidiabetic agents should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued.
Acitretin: (Major) Acitretin reduces the efficacy of oral progestin only contraceptives. Since Acitretin may cause serious birth defects, the patient should use 2 forms of reliable contraception at the same time for at least 1 month before beginning acitretin therapy, during acitretin therapy, and must continue to use them for at least 3 years after acitretin treatment has stopped. It is recommended that the patient either abstain from sexual intercourse or use 2 reliable kinds of birth control at the same time to prevent unwanted pregnancy.
Adagrasib: (Moderate) Use caution if coadministration of adagrasib with progestins is necessary, as the systemic exposure of progestins may be increased resulting in an increase in treatment-related adverse reactions. Progestins are metabolized primarily by hydroxylation via a CYP3A; adagrasib is a strong CYP3A inhibitor.
Alogliptin: (Minor) Estrogens, progestins, or oral contraceptives can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving > 50 mcg of ethinyl estradiol per day. The presence or absence of a concomitant progestin may influence the significance of this effect. Patients receiving antidiabetic agents should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued.
Alogliptin; Metformin: (Minor) Estrogens, progestins, or oral contraceptives can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving > 50 mcg of ethinyl estradiol per day. The presence or absence of a concomitant progestin may influence the significance of this effect. Patients receiving antidiabetic agents should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
Alogliptin; Pioglitazone: (Minor) Estrogens, progestins, or oral contraceptives can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving > 50 mcg of ethinyl estradiol per day. The presence or absence of a concomitant progestin may influence the significance of this effect. Patients receiving antidiabetic agents should be closely monitored for changes in diabetic control when hormone therapy is instituted or discontinued. (Minor) Progestins can impair glucose tolerance. Patients receiving antidiabetic agents should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued.
Alpha-glucosidase Inhibitors: (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Progestins can impair glucose tolerance. Patients receiving antidiabetic agents should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued.
Alprazolam: (Minor) Oral contraceptives can increase the effects of alprazolam because oral contraceptives inhibit oxidative metabolism, thereby increasing serum concentrations of concomitantly administered benzodiazepines that undergo oxidation. Patients receiving oral contraceptive therapy should be observed for evidence of increased response to alprazolam.
Amikacin: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Aminoglycosides: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Amlodipine: (Minor) Estrogen containing oral contraceptives can induce fluid retention and may increase blood pressure in some patients.
Amlodipine; Atorvastatin: (Minor) Atorvastatin can increase the plasma concentrations of oral contraceptives when the drugs are coadministered. These increases should be considered when administering atorvastatin and oral contraceptives concomitantly. (Minor) Estrogen containing oral contraceptives can induce fluid retention and may increase blood pressure in some patients.
Amlodipine; Benazepril: (Minor) Estrogen containing oral contraceptives can induce fluid retention and may increase blood pressure in some patients.
Amlodipine; Celecoxib: (Minor) Estrogen containing oral contraceptives can induce fluid retention and may increase blood pressure in some patients.
Amlodipine; Olmesartan: (Minor) Estrogen containing oral contraceptives can induce fluid retention and may increase blood pressure in some patients.
Amlodipine; Valsartan: (Minor) Estrogen containing oral contraceptives can induce fluid retention and may increase blood pressure in some patients.
Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Minor) Estrogen containing oral contraceptives can induce fluid retention and may increase blood pressure in some patients.
Amobarbital: (Major) Women taking both estrogens and barbiturates should report breakthrough bleeding to their prescribers. If used for contraception, an alternate or additional form of contraception should be considered in patients prescribed barbiturates. Higher-dose hormonal regimens may be indicated where acceptable or applicable. The alternative or additional contraceptive agent may need to be continued for 1 month after discontinuation of barbiturates. Patients taking these hormones for other indications may need to be monitored for reduced clinical effect while on barbiturates, with dose adjustments made based on clinical efficacy. Estrogens are CYP3A4 substrates and barbiturate are strong CYP3A4 inducers. Concurrent administration may increase estrogen elimination. (Moderate) Barbiturates can accelerate the hepatic clearance of progestins. For hormonal contraceptives, this interaction could result in unintended pregnancy or breakthrough bleeding. For patients regularly taking a barbiturate, an alternative or back-up method of contraception may be advisable to ensure contraceptive reliability during the use of the barbiturate, and for 1 month following the discontinuation of barbiturate use. The exception is the use of levonorgestrel progestin IUDs, which have not been reported to interact and appear to maintain reliable efficacy. Pregnancy has been reported during therapy with both estrogen- and/or progestin-based oral contraceptives in patients receiving barbiturates (e.g., phenobarbital). For patients taking progestins for other indications, like hormone replacement, monitor the patient for signs and symptoms of reduced therapeutic efficacy or need for dosage adjustment.
Amoxicillin: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Amoxicillin; Clarithromycin; Omeprazole: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available. (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available. In addition, drospirenone has antimineralocorticoid effects; the progestin may increase serum potassium. Consider monitoring serum potassium concentrations during the first month of dosing in high-risk patients who take strong CYP3A4 inhibitors long-term and concomitantly. Strong CYP3A4 inhibitors include clarithromycin.
Amoxicillin; Clavulanic Acid: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Ampicillin: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Ampicillin; Sulbactam: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Anastrozole: (Contraindicated) Estrogen therapy is not recommended during aromatase inhibitor treatment, due to opposing pharmacologic actions. Estrogens, including those found in hormonal contraceptives, could interfere competitively with the pharmacologic action of the aromatase inhibitors such as Anastrozole. The goal of aromatase inhibitor therapy is to decrease circulating estrogen concentrations and inhibit the growth of hormonally-responsive cancers. Aromatase inhibitors exhibit their antiestrogenic effects by reducing the peripheral conversion of adrenally synthesized androgens (e.g., androstenedione) to estrogens through inhibition of the aromatase enzyme.
Apalutamide: (Major) Progestins are susceptible to drug interactions with hepatic enzyme inducing drugs such as apalutamide. Concurrent administration of apalutamide with progestins, oral contraceptives, or non-oral combination contraceptives may reduce hormonal concentrations. Progestins are CYP3A4 substrates and apalutamide is a strong CYP3A4 inducer. If the hormone is used for contraception, an alternate or additional form of contraception should be considered. Higher-dose hormonal regimens may be indicated where acceptable or applicable. The alternative or additional contraceptive agent may need to be continued for 1 month after discontinuation of apalutamide. Monitor hormonal replacement therapy for loss of efficacy while on apalutamide, with dose adjustments as needed. Women taking hormonal replacement and apalutamide should report breakthrough bleeding to their prescribers. This interaction does not apply to vaginal preparations of progesterone (e.g., Crinone, Endometrin). (Major) Women taking both estrogens and apalutamide should report breakthrough bleeding to their prescribers. If used for contraception, an alternate or additional form of contraception should be considered in patients prescribed apalutamide. Higher-dose hormonal regimens may be indicated where acceptable or applicable. The alternative or additional contraceptive agent may need to be continued for 1 month after discontinuation of apalutamide. Patients taking these hormones for other indications may need to be monitored for reduced clinical effect while on apalutamide, with dose adjustments made based on clinical efficacy. Estrogens are CYP3A4 substrates and apalutamide is a strong CYP3A4 inducer. Concurrent administration may increase estrogen elimination.
Aprepitant, Fosaprepitant: (Major) If aprepitant, fosaprepitant is coadministered with hormonal contraceptives, including hormonal contraceptive devices (skin patches, implants, and hormonal IUDs), use an alternative or back-up non-hormonal method of contraception (e.g., condoms, spermicides) during treatment and for at least 1 month following the last dose of aprepitant, fosaprepitant. The efficacy of estrogens (including ethinyl estradiol) and/or progestins may be reduced when coadministered with aprepitant, fosaprepitant and for 28 days after the last dose. The exact mechanism for this interaction has not been described. Ethinyl estradiol is a CYP3A4 substrate and aprepitant, fosaprepitant is a CYP3A4 inducer; however, aprepitant, fosaprepitant is also a dose-dependent weak-to-moderate CYP3A4 inhibitor. When administered as an oral 3-day regimen (125mg/80mg/80mg) in combination with ondansetron and dexamethasone, aprepitant decreased trough concentrations of ethinyl estradiol and norethindrone by up to 64% for 3 weeks post-treatment. When ethinyl estradiol and norgestimate were administered on days 1 to 21 and aprepitant (40mg) give as a single dose on day 8, the AUC of ethinyl estradiol decreased by 4% on day 8 and by 29% on day 12; the AUC of norelgestromin increased by 18% on day 8, and decreased by 10% on day 12. Trough concentrations of both ethinyl estradiol and norelgestromin were generally lower after coadministration of aprepitant (40mg) on day 8 compared to administration without aprepitant. Specific studies have not been done with other hormonal contraceptives (e.g., progestins, non-oral combination contraceptives), an alternative or additional non-hormonal method of birth control during treatment and for 28 days after treatment is prudent to avoid potential for contraceptive failure. Additionally, although not specifically studied, because estrogens are CYP3A4 substrates, the efficacy of estrogens or progestins when used for hormone replacement may also be reduced. The clinical significance of this is not known since aprepitant, fosaprepitant is only used intermittently. (Major) If aprepitant, fosaprepitant is coadministered with hormonal contraceptives, including hormonal contraceptive devices (skin patches, implants, and hormonal IUDs), use an alternative or back-up non-hormonal method of contraception (e.g., condoms, spermicides) during treatment and for at least 1 month following the last dose of aprepitant, fosaprepitant. The efficacy of progestins may be reduced when coadministered with aprepitant, fosaprepitant and for 28 days after the last dose. The exact mechanism for this interaction has not been described. Progestins are CYP3A4 substrates and aprepitant, fosaprepitant is a CYP3A4 inducer; however, aprepitant, fosaprepitant is also a dose-dependent weak-to-moderate CYP3A4 inhibitor. When administered as an oral 3-day regimen (125mg/80mg/80mg) in combination with ondansetron and dexamethasone, aprepitant decreased trough concentrations of ethinyl estradiol and norethindrone by up to 64% for 3 weeks post-treatment. When ethinyl estradiol and norgestimate were administered on days 1 to 21 and aprepitant (40mg) give as a single dose on day 8, the AUC of ethinyl estradiol decreased by 4% on day 8 and by 29% on day 12; the AUC of norelgestromin increased by 18% on day 8, and decreased by 10% on day 12. Trough concentrations of both ethinyl estradiol and norelgestromin were generally lower after coadministration of aprepitant (40mg) on day 8 compared to administration without aprepitant. Specific studies have not been done with other hormonal contraceptives (e.g., progestins, non-oral combination contraceptives), an alternative or additional non-hormonal method of birth control during treatment and for 28 days after treatment is prudent to avoid potential for contraceptive failure. The clinical significance of this is not known since aprepitant, fosaprepitant is only used intermittently.
Armodafinil: (Major) Armodafinil may cause failure of oral contraceptives or hormonal contraceptive-containing implants or devices due to induction of CYP3A4 isoenzyme metabolism of estradiol, ethinyl estradiol and/or the progestins in these products. Female patients of child-bearing potential should be advised to discuss contraceptive options with their health care provider to prevent unintended pregnancies. An alternative method or an additional method of contraception should be utilized during armodafinil therapy and continued for one month after armodafinil discontinuation. (Major) Armodafinil may cause failure of oral contraceptives or hormonal contraceptive-containing implants or devices due to induction of CYP3A4 isoenzyme metabolism of estrogens and/or the progestins in these products. Female patients of child-bearing potential should be advised to discuss contraceptive options with their health care provider to prevent unintended pregnancies. An alternative method or an additional method of contraception should be utilized during armodafinil therapy and continued for one month after armodafinil discontinuation.
Artemether; Lumefantrine: (Major) Although no formal drug interaction studies have been performed, the manufacturer states that artemether; lumefantrine may reduce the effectiveness of hormonal contraceptives, including non-oral combination contraceptives, oral contraceptives, and progestin contraceptives (i.e. norethindrone). This may be due to a CYP3A4 interaction. Artemether; lumefantrine is a substrate and ethinyl estradiol is a substrate/inhibitor of the CYP3A4 isoenzyme. Additional use of a non-hormonal method of birth control is recommended. (Major) Although no formal drug interaction studies have been performed, the manufacturer states that artemether; lumefantrine may reduce the effectiveness of hormonal contraceptives, including oral contraceptives. This may be due to a CYP3A4 interaction. Artemether; lumefantrine is a substrate and ethinyl estradiol is a substrate/inhibitor of the CYP3A4 isoenzyme. Additional use of a non-hormonal method of birth control is recommended. (Major) Although no formal drug interaction studies have been performed, the manufacturer states that artemether; lumefantrine may reduce the effectiveness of hormonal treatments, including progestin-only contraceptives (e.g., norethindrone). This may be due to a CYP3A4 interaction. Additional use of a non-hormonal method of birth control is recommended when norethindrone is used for birth control. Women receiving norethindrone hormone replacement or contraceptives with artemether; lumefantrine should be instructed to report any breakthrough bleeding or other adverse effects to their prescribers.
Ascorbic Acid, Vitamin C: (Minor) Ascorbic acid, vitamin C acts as a competitive inhibitor of the sulfation of ethinyl estradiol in the gastrointestinal tract wall and may increase the bioavailability by 50%. Patients who ingest ascorbic acid supplements may experience an increase in estrogen related side effects.
Aspirin, ASA; Butalbital; Caffeine: (Major) Women taking both estrogens and barbiturates should report breakthrough bleeding to their prescribers. If used for contraception, an alternate or additional form of contraception should be considered in patients prescribed barbiturates. Higher-dose hormonal regimens may be indicated where acceptable or applicable. The alternative or additional contraceptive agent may need to be continued for 1 month after discontinuation of barbiturates. Patients taking these hormones for other indications may need to be monitored for reduced clinical effect while on barbiturates, with dose adjustments made based on clinical efficacy. Estrogens are CYP3A4 substrates and barbiturate are strong CYP3A4 inducers. Concurrent administration may increase estrogen elimination. (Moderate) Barbiturates can accelerate the hepatic clearance of progestins. For hormonal contraceptives, this interaction could result in unintended pregnancy or breakthrough bleeding. For patients regularly taking a barbiturate, an alternative or back-up method of contraception may be advisable to ensure contraceptive reliability during the use of the barbiturate, and for 1 month following the discontinuation of barbiturate use. The exception is the use of levonorgestrel progestin IUDs, which have not been reported to interact and appear to maintain reliable efficacy. Pregnancy has been reported during therapy with both estrogen- and/or progestin-based oral contraceptives in patients receiving barbiturates (e.g., phenobarbital). For patients taking progestins for other indications, like hormone replacement, monitor the patient for signs and symptoms of reduced therapeutic efficacy or need for dosage adjustment. (Minor) Serum concentrations of caffeine may be increased during concurrent administration with ethinyl estradiol. Patients may desire to limit products that contain high amounts of caffeine to minimize caffeine-related side effects such as nausea or tremors.
Aspirin, ASA; Butalbital; Caffeine; Codeine: (Major) Women taking both estrogens and barbiturates should report breakthrough bleeding to their prescribers. If used for contraception, an alternate or additional form of contraception should be considered in patients prescribed barbiturates. Higher-dose hormonal regimens may be indicated where acceptable or applicable. The alternative or additional contraceptive agent may need to be continued for 1 month after discontinuation of barbiturates. Patients taking these hormones for other indications may need to be monitored for reduced clinical effect while on barbiturates, with dose adjustments made based on clinical efficacy. Estrogens are CYP3A4 substrates and barbiturate are strong CYP3A4 inducers. Concurrent administration may increase estrogen elimination. (Moderate) Barbiturates can accelerate the hepatic clearance of progestins. For hormonal contraceptives, this interaction could result in unintended pregnancy or breakthrough bleeding. For patients regularly taking a barbiturate, an alternative or back-up method of contraception may be advisable to ensure contraceptive reliability during the use of the barbiturate, and for 1 month following the discontinuation of barbiturate use. The exception is the use of levonorgestrel progestin IUDs, which have not been reported to interact and appear to maintain reliable efficacy. Pregnancy has been reported during therapy with both estrogen- and/or progestin-based oral contraceptives in patients receiving barbiturates (e.g., phenobarbital). For patients taking progestins for other indications, like hormone replacement, monitor the patient for signs and symptoms of reduced therapeutic efficacy or need for dosage adjustment. (Minor) Serum concentrations of caffeine may be increased during concurrent administration with ethinyl estradiol. Patients may desire to limit products that contain high amounts of caffeine to minimize caffeine-related side effects such as nausea or tremors.
Aspirin, ASA; Caffeine: (Minor) Serum concentrations of caffeine may be increased during concurrent administration with ethinyl estradiol. Patients may desire to limit products that contain high amounts of caffeine to minimize caffeine-related side effects such as nausea or tremors.
Aspirin, ASA; Caffeine; Orphenadrine: (Minor) Serum concentrations of caffeine may be increased during concurrent administration with ethinyl estradiol. Patients may desire to limit products that contain high amounts of caffeine to minimize caffeine-related side effects such as nausea or tremors.
Atazanavir: (Major) Atazanavir may decrease the metabolism of oral contraceptives and non-oral combination contraceptives; the mean exposure and minimum serum concentrations of ethinyl estradiol and norethindrone are increased when administered with atazanavir 400 mg daily. However, if atazanavir is boosted with ritonavir, mean exposure of ethinyl estradiol will be decreased; data are limited regarding use of atazanavir with cobicistat. Instruct women to report any breakthrough bleeding or other adverse effects (e.g., insulin resistance, dyslipidemia, and acne) to their prescribers. It may be prudent for women who receive hormonal contraceptives with atazanavir boosted with ritonavir or cobicistat to use an additional method of contraception to protect against unwanted pregnancy. Further, because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, HIV-infected women should use an additional barrier method of contraception such as condoms. (Major) If ethinyl estradiol is administered with atazanavir boosted with ritonavir, it is recommended that the dose of ethinyl estradiol be at least 35 mcg. However, the dose of ethinyl estradiol should be no more than 30 mcg when administered with atazanavir that is NOT boosted by ritonavir. The mean exposure and minimum serum concentrations of ethinyl estradiol are increased when administered with atazanavir; but if atazanavir is boosted with ritonavir, mean exposure of ethinyl estradiol will be decreased. Data are limited regarding use of atazanavir with cobicistat. Instruct women to report any breakthrough bleeding or other adverse effects to their prescribers. It may be prudent for women who receive hormonal contraceptives with atazanavir boosted with ritonavir or cobicistat to use an additional method of contraception to protect against unwanted pregnancy. Further, because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, HIV-infected women should use an additional barrier method of contraception such as condoms.
Atazanavir; Cobicistat: (Major) Atazanavir may decrease the metabolism of oral contraceptives and non-oral combination contraceptives; the mean exposure and minimum serum concentrations of ethinyl estradiol and norethindrone are increased when administered with atazanavir 400 mg daily. However, if atazanavir is boosted with ritonavir, mean exposure of ethinyl estradiol will be decreased; data are limited regarding use of atazanavir with cobicistat. Instruct women to report any breakthrough bleeding or other adverse effects (e.g., insulin resistance, dyslipidemia, and acne) to their prescribers. It may be prudent for women who receive hormonal contraceptives with atazanavir boosted with ritonavir or cobicistat to use an additional method of contraception to protect against unwanted pregnancy. Further, because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, HIV-infected women should use an additional barrier method of contraception such as condoms. (Major) Consider the benefits and risk of administering antiretroviral regimens containing cobicistat with norethindrone. Insufficient data are available to make dosage recommendations, particularly when cobicistat is combined in other antiviral regimens. It is not clear how cobicistat alters various progestin-only agents used for contraception, fertility or luteal support, or for hormone replacement therapy (HRT). Instruct women to report any breakthrough bleeding or other adverse effects (e.g., insulin resistance, dyslipidemia, and acne) to their prescribers. There is a potential for altered efficacy for combined hormonal contraceptives. Consider alternative methods of contraception, such as condoms, to prevent unwanted pregnancy and transmission of HIV/AIDS. When progestins are used for other purposes, monitor for altered clinical response to hormonal therapy. (Major) If ethinyl estradiol is administered with atazanavir boosted with ritonavir, it is recommended that the dose of ethinyl estradiol be at least 35 mcg. However, the dose of ethinyl estradiol should be no more than 30 mcg when administered with atazanavir that is NOT boosted by ritonavir. The mean exposure and minimum serum concentrations of ethinyl estradiol are increased when administered with atazanavir; but if atazanavir is boosted with ritonavir, mean exposure of ethinyl estradiol will be decreased. Data are limited regarding use of atazanavir with cobicistat. Instruct women to report any breakthrough bleeding or other adverse effects to their prescribers. It may be prudent for women who receive hormonal contraceptives with atazanavir boosted with ritonavir or cobicistat to use an additional method of contraception to protect against unwanted pregnancy. Further, because hormonal contraceptives do not protect against the transmission of HIV/AIDS and other sexually transmitted diseases, HIV-infected women should use an additional barrier method of contraception such as condoms. (Moderate) Consider the benefits and risk of administering antiretroviral regimens containing cobicistat with estrogens, such as ethinyl estradiol, or mestranol, which is converted to ethinyl estradiol. There is a potential for altered efficacy for combined hormonal contraceptives. Insufficient data are available to make dosage recommendations, particularly when cobicistat is used in combination regimens with other antiviral therapies. Consider alternative or additional methods of contraception, such as condoms, to prevent unwanted pregnancy and transmission of HIV/AIDS. When patients are taking estrogen for hormone replacement therapy (HRT), it may be prudent to monitor for reduced clinical efficacy or unusual vaginal bleeding patterns.
Atorvastatin: (Minor) Atorvastatin can increase the plasma concentrations of oral contraceptives when the drugs are coadministered. These increases should be considered when administering atorvastatin and oral contraceptives concomitantly.
Atorvastatin; Ezetimibe: (Minor) Atorvastatin can increase the plasma concentrations of oral contraceptives when the drugs are coadministered. These increases should be considered when administering atorvastatin and oral contraceptives concomitantly.
Azelastine; Fluticasone: (Moderate) Monitor for corticosteroid-related adverse events if corticosteroids are used with estrogens. Concurrent use may increase the exposure of corticosteroids. Estrogens may decrease the hepatic clearance of corticosteroids thereby increasing their effect.
Azithromycin: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Aztreonam: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Bacitracin: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Barbiturates: (Major) Women taking both estrogens and barbiturates should report breakthrough bleeding to their prescribers. If used for contraception, an alternate or additional form of contraception should be considered in patients prescribed barbiturates. Higher-dose hormonal regimens may be indicated where acceptable or applicable. The alternative or additional contraceptive agent may need to be continued for 1 month after discontinuation of barbiturates. Patients taking these hormones for other indications may need to be monitored for reduced clinical effect while on barbiturates, with dose adjustments made based on clinical efficacy. Estrogens are CYP3A4 substrates and barbiturate are strong CYP3A4 inducers. Concurrent administration may increase estrogen elimination. (Moderate) Barbiturates can accelerate the hepatic clearance of progestins. For hormonal contraceptives, this interaction could result in unintended pregnancy or breakthrough bleeding. For patients regularly taking a barbiturate, an alternative or back-up method of contraception may be advisable to ensure contraceptive reliability during the use of the barbiturate, and for 1 month following the discontinuation of barbiturate use. The exception is the use of levonorgestrel progestin IUDs, which have not been reported to interact and appear to maintain reliable efficacy. Pregnancy has been reported during therapy with both estrogen- and/or progestin-based oral contraceptives in patients receiving barbiturates (e.g., phenobarbital). For patients taking progestins for other indications, like hormone replacement, monitor the patient for signs and symptoms of reduced therapeutic efficacy or need for dosage adjustment.
Beclomethasone: (Moderate) Monitor for corticosteroid-related adverse events if corticosteroids are used with estrogens. Concurrent use may increase the exposure of corticosteroids. Estrogens may decrease the hepatic clearance of corticosteroids thereby increasing their effect.
Belzutifan: (Major) Women taking both estrogens and belzutifan should report breakthrough bleeding to their prescribers. If used for contraception, an alternate or additional form of contraception should be considered in patients prescribed belzutifan. Higher-dose hormonal regimens may be indicated where acceptable or applicable. The alternative or additional contraceptive agent may need to be continued for 1 month after discontinuation of belzutifan. Patients taking these hormones for other indications may need to be monitored for reduced clinical effect while on belzutifan, with dose adjustments made based on clinical efficacy. Estrogens are CYP3A4 substrates and belzutifan is a weak CYP3A4 inducer. Concurrent administration may increase estrogen elimination. (Major) Women taking both progestins and belzutifan should report breakthrough bleeding to their prescribers. An alternate or additional form of contraception should be considered in patients prescribed belzutifan. Higher-dose hormonal regimens may be indicated where acceptable or applicable. The alternative or additional contraceptive agent may need to be continued for 1 month after discontinuation of belzutifan. For patients on hormone replacement treatments (HRT) with progestins, monitor for altered clinical response, such as increased hot flashes, vaginal dryness, changes in withdrawal bleeding, or other signs of decreased hormonal efficacy. Progestins are CYP3A4 substrates and belzutifan is a weak CYP3A4 inducer.
Benzhydrocodone; Acetaminophen: (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.
Betamethasone: (Moderate) Monitor for corticosteroid-related adverse events if corticosteroids are used with estrogens. Concurrent use may increase the exposure of corticosteroids. Estrogens may decrease the hepatic clearance of corticosteroids thereby increasing their effect.
Bexarotene: (Major) Bexarotene capsules may theoretically increase the rate of metabolism and reduce plasma concentrations of substrates metabolized by CYP3A4, including oral contraceptives. It is recommended that two reliable forms of contraception be used simultaneously during oral bexarotene therapy. It is strongly recommended that one of the forms of contraception be non-hormonal. Additionally, because of possible CYP3A4 induction, bexarotene may also decrease the efficacy of hormones used for hormone replacement therapy. (Major) Women taking both estrogens and bexarotene should report breakthrough bleeding to their prescribers. If used for contraception, an alternate or additional form of contraception should be considered in patients prescribed bexarotene. Higher-dose hormonal regimens may be indicated where acceptable or applicable. The alternative or additional contraceptive agent may need to be continued for 1 month after discontinuation of bexarotene. Patients taking these hormones for other indications may need to be monitored for reduced clinical effect while on bexarotene, with dose adjustments made based on clinical efficacy. Estrogens are CYP3A4 substrates and bexarotene is a moderate CYP3A4 inducer. Concurrent administration may increase estrogen elimination.
Bismuth Subcitrate Potassium; Metronidazole; Tetracycline: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Bismuth Subsalicylate; Metronidazole; Tetracycline: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Blinatumomab: (Moderate) No drug interaction studies have been performed with blinatumomab. The drug may cause a transient release of cytokines leading to an inhibition of CYP450 enzymes. The interaction risk with CYP450 substrates is likely the highest during the first 9 days of the first cycle and the first 2 days of the second cycle. Monitor patients receiving concurrent CYP450 substrates that have a narrow therapeutic index (NTI) such as ethinyl estradiol. The dose of the concomitant drug may need to be adjusted.
Bosentan: (Major) Hormonal contraceptives should not be used as the sole method to prevent pregnancy in patients receiving bosentan. There is a possibility of contraceptive failure when bosentan is coadministered with products containing estrogens and/or progestins. Bosentan is teratogenic. To prevent pregnancy, females of reproductive potential must use 2 acceptable contraception methods during treatment and for 1 month after discontinuation of bosentan therapy. The patient may choose 1 highly effective contraceptive form, including an intrauterine device (IUD) or tubal sterilization, a combination of a hormonal contraceptive with a barrier method, or 2 barrier methods. If a male partner's vasectomy is chosen as a method of contraception, a hormonal or barrier method must still be used by the female patient. Hormonal contraceptives, including oral contraceptives or non-oral combination contraceptives (injectable, transdermal, and implantable contraceptives) may not be reliably effective in the presence of bosentan, since many contraceptive drugs are metabolized by CYP3A4 isoenzymes and bosentan is a significant inducer of CYP3A enzymes. Decreases in hormonal exposure have been documented in drug interaction studies of bosentan with hormonal contraception. Additionally, estrogens and progestins used for hormone replacement therapy (HRT) may also be less effective; patients should be monitored for changes in efficacy such as breakthrough bleeding or an increase in hot flashes. Dosage adjustments may be necessary. (Major) Hormonal contraceptives should not be used as the sole method to prevent pregnancy in patients receiving bosentan. There is a possibility of contraceptive failure when bosentan is coadministered with products containing estrogens and/or progestins. Bosentan is teratogenic. To prevent pregnancy, females of reproductive potential must use two acceptable contraception methods during treatment and for one month after discontinuation of bosentan therapy. The patient may choose one highly effective contraceptive form, including an intrauterine device (IUD) or tubal sterilization, a combination of a hormonal contraceptive with a barrier method, or two barrier methods. If a male partner's vasectomy is chosen as a method of contraception, a hormonal or barrier method must still be used by the female patient. Patients taking these hormones for other indications may need to be monitored for reduced clinical effect while on bosentan, with dose adjustments made based on clinical efficacy. Estrogens are CYP3A4 substrates and bosentan is a moderate CYP3A4 inducer. Concurrent administration may increase estrogen elimination.
Bromocriptine: (Minor) Bromocriptine is used to restore ovulation and ovarian function in amenorrheic women. Estrogens and progestins can cause amenorrhea and, therefore, counteract the desired effects of bromocriptine. Concurrent use is not recommended; an alternate form of contraception is recommended during bromocriptine therapy. (Minor) Bromocriptine is used to restore ovulation and ovarian function in amenorrheic women. Progestins can cause amenorrhea and, therefore, counteract the desired effects of bromocriptine. Concurrent use is not recommended; an alternate form of contraception is recommended during bromocriptine therapy.
Budesonide: (Moderate) Monitor for corticosteroid-related adverse events if corticosteroids are used with estrogens. Concurrent use may increase the exposure of corticosteroids. Estrogens may decrease the hepatic clearance of corticosteroids thereby increasing their effect.
Budesonide; Formoterol: (Moderate) Monitor for corticosteroid-related adverse events if corticosteroids are used with estrogens. Concurrent use may increase the exposure of corticosteroids. Estrogens may decrease the hepatic clearance of corticosteroids thereby increasing their effect.
Budesonide; Glycopyrrolate; Formoterol: (Moderate) Monitor for corticosteroid-related adverse events if corticosteroids are used with estrogens. Concurrent use may increase the exposure of corticosteroids. Estrogens may decrease the hepatic clearance of corticosteroids thereby increasing their effect.
Butabarbital: (Major) Women taking both estrogens and barbiturates should report breakthrough bleeding to their prescribers. If used for contraception, an alternate or additional form of contraception should be considered in patients prescribed barbiturates. Higher-dose hormonal regimens may be indicated where acceptable or applicable. The alternative or additional contraceptive agent may need to be continued for 1 month after discontinuation of barbiturates. Patients taking these hormones for other indications may need to be monitored for reduced clinical effect while on barbiturates, with dose adjustments made based on clinical efficacy. Estrogens are CYP3A4 substrates and barbiturate are strong CYP3A4 inducers. Concurrent administration may increase estrogen elimination. (Moderate) Barbiturates can accelerate the hepatic clearance of progestins. For hormonal contraceptives, this interaction could result in unintended pregnancy or breakthrough bleeding. For patients regularly taking a barbiturate, an alternative or back-up method of contraception may be advisable to ensure contraceptive reliability during the use of the barbiturate, and for 1 month following the discontinuation of barbiturate use. The exception is the use of levonorgestrel progestin IUDs, which have not been reported to interact and appear to maintain reliable efficacy. Pregnancy has been reported during therapy with both estrogen- and/or progestin-based oral contraceptives in patients receiving barbiturates (e.g., phenobarbital). For patients taking progestins for other indications, like hormone replacement, monitor the patient for signs and symptoms of reduced therapeutic efficacy or need for dosage adjustment.
Butalbital; Acetaminophen: (Major) Women taking both estrogens and barbiturates should report breakthrough bleeding to their prescribers. If used for contraception, an alternate or additional form of contraception should be considered in patients prescribed barbiturates. Higher-dose hormonal regimens may be indicated where acceptable or applicable. The alternative or additional contraceptive agent may need to be continued for 1 month after discontinuation of barbiturates. Patients taking these hormones for other indications may need to be monitored for reduced clinical effect while on barbiturates, with dose adjustments made based on clinical efficacy. Estrogens are CYP3A4 substrates and barbiturate are strong CYP3A4 inducers. Concurrent administration may increase estrogen elimination. (Moderate) Barbiturates can accelerate the hepatic clearance of progestins. For hormonal contraceptives, this interaction could result in unintended pregnancy or breakthrough bleeding. For patients regularly taking a barbiturate, an alternative or back-up method of contraception may be advisable to ensure contraceptive reliability during the use of the barbiturate, and for 1 month following the discontinuation of barbiturate use. The exception is the use of levonorgestrel progestin IUDs, which have not been reported to interact and appear to maintain reliable efficacy. Pregnancy has been reported during therapy with both estrogen- and/or progestin-based oral contraceptives in patients receiving barbiturates (e.g., phenobarbital). For patients taking progestins for other indications, like hormone replacement, monitor the patient for signs and symptoms of reduced therapeutic efficacy or need for dosage adjustment. (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.
Butalbital; Acetaminophen; Caffeine: (Major) Women taking both estrogens and barbiturates should report breakthrough bleeding to their prescribers. If used for contraception, an alternate or additional form of contraception should be considered in patients prescribed barbiturates. Higher-dose hormonal regimens may be indicated where acceptable or applicable. The alternative or additional contraceptive agent may need to be continued for 1 month after discontinuation of barbiturates. Patients taking these hormones for other indications may need to be monitored for reduced clinical effect while on barbiturates, with dose adjustments made based on clinical efficacy. Estrogens are CYP3A4 substrates and barbiturate are strong CYP3A4 inducers. Concurrent administration may increase estrogen elimination. (Moderate) Barbiturates can accelerate the hepatic clearance of progestins. For hormonal contraceptives, this interaction could result in unintended pregnancy or breakthrough bleeding. For patients regularly taking a barbiturate, an alternative or back-up method of contraception may be advisable to ensure contraceptive reliability during the use of the barbiturate, and for 1 month following the discontinuation of barbiturate use. The exception is the use of levonorgestrel progestin IUDs, which have not been reported to interact and appear to maintain reliable efficacy. Pregnancy has been reported during therapy with both estrogen- and/or progestin-based oral contraceptives in patients receiving barbiturates (e.g., phenobarbital). For patients taking progestins for other indications, like hormone replacement, monitor the patient for signs and symptoms of reduced therapeutic efficacy or need for dosage adjustment. (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. (Minor) Serum concentrations of caffeine may be increased during concurrent administration with ethinyl estradiol. Patients may desire to limit products that contain high amounts of caffeine to minimize caffeine-related side effects such as nausea or tremors.
Butalbital; Acetaminophen; Caffeine; Codeine: (Major) Women taking both estrogens and barbiturates should report breakthrough bleeding to their prescribers. If used for contraception, an alternate or additional form of contraception should be considered in patients prescribed barbiturates. Higher-dose hormonal regimens may be indicated where acceptable or applicable. The alternative or additional contraceptive agent may need to be continued for 1 month after discontinuation of barbiturates. Patients taking these hormones for other indications may need to be monitored for reduced clinical effect while on barbiturates, with dose adjustments made based on clinical efficacy. Estrogens are CYP3A4 substrates and barbiturate are strong CYP3A4 inducers. Concurrent administration may increase estrogen elimination. (Moderate) Barbiturates can accelerate the hepatic clearance of progestins. For hormonal contraceptives, this interaction could result in unintended pregnancy or breakthrough bleeding. For patients regularly taking a barbiturate, an alternative or back-up method of contraception may be advisable to ensure contraceptive reliability during the use of the barbiturate, and for 1 month following the discontinuation of barbiturate use. The exception is the use of levonorgestrel progestin IUDs, which have not been reported to interact and appear to maintain reliable efficacy. Pregnancy has been reported during therapy with both estrogen- and/or progestin-based oral contraceptives in patients receiving barbiturates (e.g., phenobarbital). For patients taking progestins for other indications, like hormone replacement, monitor the patient for signs and symptoms of reduced therapeutic efficacy or need for dosage adjustment. (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. (Minor) Serum concentrations of caffeine may be increased during concurrent administration with ethinyl estradiol. Patients may desire to limit products that contain high amounts of caffeine to minimize caffeine-related side effects such as nausea or tremors.
Cabozantinib: (Minor) Monitor for an increase in ethinyl estradiol-related adverse reactions if coadministration with cabozantinib is necessary. Ethinyl estradiol is a P-glycoprotein (P-gp) substrate. Cabozantinib is a P-gp inhibitor and has the potential to increase plasma concentrations of P-gp substrates; however, the clinical relevance of this finding is unknown.
Caffeine: (Minor) Serum concentrations of caffeine may be increased during concurrent administration with ethinyl estradiol. Patients may desire to limit products that contain high amounts of caffeine in an effort to minimize caffeine-related side effects such as nausea or tremors. (Minor) Serum concentrations of caffeine may be increased during concurrent administration with ethinyl estradiol. Patients may desire to limit products that contain high amounts of caffeine to minimize caffeine-related side effects such as nausea or tremors.
Caffeine; Sodium Benzoate: (Minor) Serum concentrations of caffeine may be increased during concurrent administration with ethinyl estradiol. Patients may desire to limit products that contain high amounts of caffeine to minimize caffeine-related side effects such as nausea or tremors.
Calaspargase pegol: (Major) The concomitant use of calaspargase pegol and oral contraceptives may reduce the efficacy of oral contraceptives. Women of reproductive potential should use a non-hormonal method of birth control during therapy and for at least 3 months after the last calaspargase pegol dose due to the risk of fetal harm.
Calcium: (Minor) Estrogens can increase calcium absorption. Use caution in patients predisposed to hypercalcemia or nephrolithiasis.
Calcium-channel blockers: (Minor) Estrogen containing oral contraceptives can induce fluid retention and may increase blood pressure in some patients.
Canagliflozin: (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Progestins can impair glucose tolerance. Patients receiving antidiabetic agents should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued.
Canagliflozin; Metformin: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Progestins can impair glucose tolerance. Patients receiving antidiabetic agents should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued.
Carbamazepine: (Major) Advise patients taking estrogen hormones for contraception to consider an alternate or additional form of contraception, such as nonhormonal and/or barrier methods, during and for at least 1 month following discontinuation of carbamazepine. Higher-dose hormonal regimens containing a minimum of 30 mcg of ethinyl estradiol or equivalent may also be considered. Patients taking these hormones for other indications may need to be monitored for reduced clinical effect while on carbamazepine, with dose adjustments made based on clinical efficacy. Estrogens are CYP3A substrates and carbamazepine is a strong CYP3A inducer. Concurrent administration may increase estrogen elimination. (Major) Advise patients taking progestin hormones for contraception to consider an alternate or additional form of contraception, such as nonhormonal and/or barrier methods, during and for at least 1 month following discontinuation of carbamazepine. Higher-dose hormonal regimens may also be considered. Patients taking these hormones for other indications may need to be monitored for reduced clinical effect while on carbamazepine, with dose adjustments made based on clinical efficacy. Progestins are CYP3A substrates and carbamazepine is a strong CYP3A inducer. Concurrent administration may increase progestin elimination. This interaction does not apply to vaginal preparations of progesterone (e.g., Crinone, Endometrin).
Carbapenems: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Cefaclor: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Cefadroxil: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily identified and the true incidence of such events may be under-reported, and given the serious consequence of unwanted pregnancy, that recommending an additional method of contraception during short-term antibiotic use may be justified. During long-term antibiotic administration, the risk for drug interaction with OCs is less clear, but alternative or additional contraception may be advisable in selected circumstances. Data regarding progestin-only contraceptives or for newer combined contraceptive deliveries (e.g., patches, rings) are not available.
Cefazolin: (Moderate) It would be prudent to recommend alternative or additional contraception when oral contraceptives (OCs) are used in conjunction with antibiotics. It was previously thought that antibiotics may decrease the effectiveness of OCs containing estrogens due to stimulation of metabolism or a reduction in enterohepatic circulation via changes in GI flora. One retrospective study reviewed the literature to determine the effects of oral antibiotics on the pharmacokinetics of contraceptive estrogens and progestins, and also examined clinical studies in which the incidence of pregnancy with OCs and antibiotics was reported. It was concluded that the antibiotics ampicillin, ciprofloxacin, clarithromycin, doxycycline, metronidazole, ofloxacin, roxithromycin, temafloxacin, and tetracycline did not alter plasma concentrations of OCs. Antituberculous drugs (e.g., rifampin) were the only agents associated with OC failure and pregnancy. Based on the study results, these authors recommended that back-up contraception may not be necessary if OCs are used reliably during oral antibiotic use. Another review concurred with these data, but noted that individual patients have been identified who experienced significant decreases in plasma concentrations of combined OC components and who appeared to ovulate; the agents most often associated with these changes were rifampin, tetracyclines, and penicillin derivatives. These authors concluded that because females most at risk for OC failure or noncompliance may not be easily