NORCEPT-E 1/35 28
Clinical safety rating
cautionComprehensive clinical and safety monograph for NORCEPT-E 1/35 28 (NORCEPT-E 1/35 28).
Combination estrogen (ethinyl estradiol) and progestin (norethindrone) contraceptive: suppresses gonadotropin release, inhibits ovulation, thickens cervical mucus, and alters endometrial lining.
| Metabolism | Ethinyl estradiol: primarily metabolized by CYP3A4; norethindrone: primarily metabolized by CYP3A4 and CYP2C9. |
| Excretion | Renal (primarily as metabolites) and fecal; approximately 50-60% excreted in urine, 30-40% in feces. Ethinyl estradiol and norethindrone are extensively metabolized via hydroxylation and conjugation; glucuronide and sulfate conjugates are eliminated in urine and bile. |
| Half-life | Norethindrone: 5-14 hours; ethinyl estradiol: 13-27 hours. The terminal half-life of norethindrone is about 10 hours, allowing once-daily dosing; ethinyl estradiol's longer half-life contributes to steady-state concentrations within 3-5 days. |
| Protein binding | Norethindrone: >97% bound to albumin and SHBG; ethinyl estradiol: >97% bound to albumin. Ethinyl estradiol also binds to SHBG with lower affinity. |
| Volume of Distribution | Norethindrone: approximately 3.5 L/kg; ethinyl estradiol: approximately 2.5 L/kg. These values reflect extensive tissue distribution and binding to tissues such as breast, uterus, and adipose. |
| Bioavailability | Oral: Norethindrone ~64% (first-pass metabolism); ethinyl estradiol ~40-50% (extensive first-pass metabolism). Factors such as food and individual differences may affect bioavailability. |
| Onset of Action | Oral: 1-2 hours for hormonal effects; contraceptive efficacy requires 7 days of consistent dosing for full suppression of ovulation. Effects on cervical mucus and endometrium begin within the first few days. |
| Duration of Action | 24 hours for contraceptive effect with daily dosing. Withdrawal bleeding occurs 2-3 days after the last active pill. Hormonal effects persist for about 7 days after discontinuation before ovulation may resume. |
| Molecular Weight | 298.42 |
1 tablet orally once daily for 21 days, followed by 7 days of placebo tablets.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment. Contraindicated in acute renal disease or marked renal impairment. |
| Liver impairment | Contraindicated in severe hepatic disease or liver tumors (benign or malignant). Use with caution in mild to moderate hepatic impairment; dose adjustment generally not required but monitor for adverse effects. |
| Pediatric use | Not indicated for use before menarche. After menarche, use same adult dosing schedule. |
| Geriatric use | No specific dose adjustment; use with caution due to increased risk of thromboembolic disorders and cardiovascular events in women over 35 who smoke. |
| 1st trimester | NORCEPT-E 1/35 28 (norethindrone/ethinyl estradiol) is contraindicated during pregnancy. Use in first trimester is associated with risk of fetal harm including congenital anomalies (e.g., cardiovascular, limb reduction). Discontinue if pregnancy occurs. |
| 2nd trimester | Same risks as first trimester; fetal exposure to sex hormones may cause urogenital abnormalities. Not indicated during pregnancy. |
| 3rd trimester | Same as second trimester; avoid use during pregnancy. |
Clinical note
Comprehensive clinical and safety monograph for NORCEPT-E 1/35 28 (NORCEPT-E 1/35 28).
| Placental transfer | Both components cross the placenta. Ethinyl estradiol levels in fetal plasma are 20-50% of maternal levels; norethindrone levels are similar. Documented transfer with potential for fetal effects. |
| Breastfeeding | Norethindrone and ethinyl estradiol are excreted in breast milk in small amounts. Combination oral contraceptives may reduce milk production and composition, especially in early postpartum. Use alternative contraception until weaning. Monitor infant for jaundice and growth. |
| Lactation Rating | L3 (Moderately Safe) - limited data suggest risk, but generally considered compatible with caution. Alternative methods preferred. |
| Teratogenic Risk | First trimester: Increased risk of neural tube defects, cardiovascular malformations, and limb reduction defects if inadvertently exposed to the progestin component (norethindrone) at high doses. Second and third trimesters: No evidence of teratogenicity from estrogen-progestin combinations; however, androgenic effects (pseudohermaphroditism in female fetuses) have been reported with high doses of progestins. Overall, combination oral contraceptives are contraindicated in pregnancy. |
| Fetal Monitoring | Monitor blood pressure (risk of hypertension), liver function (cholestasis), and glucose tolerance (insulin resistance). Assess for thrombotic events (DVT, PE) due to estrogen component. In fetus: ultrasound if inadvertent pregnancy exposure occurs. |
| Fertility Effects | Suppresses ovulation via inhibition of gonadotropin release. Return to fertility is typically rapid (within 1-2 cycles) after discontinuation. No permanent negative effects on fertility. |
■ FDA Black Box Warning
Cigarette smoking increases risk of serious cardiovascular events (thrombosis, stroke, myocardial infarction) from combination oral contraceptives, especially in women over 35 and heavy smokers (>15 cigarettes/day).
| Serious Effects |
PregnancyBreast cancerEstrogen-dependent neoplasiaUndiagnosed abnormal genital bleedingActive liver disease or hepatic adenomaHistory of or current thromboembolic disorders (e.g., DVT, PE)Cerebrovascular diseaseCoronary artery diseaseKnown thrombophilic conditions (e.g., Factor V Leiden)Uncontrolled hypertensionMigraine with aura (especially if age >35)Diabetes with vascular involvementMajor surgery with prolonged immobilizationHypersensitivity to any component
| Precautions | Thrombotic disorders (DVT, PE, stroke, MI), Hepatic tumors, Hypertension, Gallbladder disease, Carbohydrate/lipid metabolism effects, Ocular lesions (retinal thrombosis), Hereditary angioedema, Chloasma, Depression |
| Food/Dietary | No significant food interactions. Grapefruit juice does not affect ethinyl estradiol. Avoid St. John's wort (herbal supplement) as it reduces contraceptive efficacy. |
| Clinical Pearls | NORCEPT-E 1/35 28 is a combination oral contraceptive containing ethinyl estradiol 35 mcg and norethindrone 1 mg. It is indicated for contraception and may be used off-label for menstrual disorders. Pearl: Counsel patients that missed pills increase pregnancy risk; refer to prescribing information for missed dose instructions. Monitor for thromboembolic events, especially in smokers over 35. Drug interactions: rifampin, certain anticonvulsants (e.g., phenytoin, carbamazepine), and St. John's wort reduce efficacy. Breakthrough bleeding common in first 3 cycles; if persistent, evaluate for non-compliance or alternative causes. |
| Patient Advice | Take one pill daily at the same time, preferably after an evening meal or at bedtime to minimize nausea. · Missed pill? Take as soon as remembered; if >48 hours, use backup contraception (condoms) for 7 days and consult the package insert. · Report immediately: severe leg pain/chest pain/sudden shortness of breath (signs of blood clot), severe headache, vision changes, or jaundice. · Smoking increases risk of serious cardiovascular side effects; avoid smoking especially if over 35. · May decrease efficacy with certain antibiotics (non-rifampin) – use backup contraception during antibiotic course and for 7 days after. · Do not take if pregnant, breastfeeding, or have history of blood clots, stroke, breast cancer, liver disease, or migraine with aura. |
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