GENCEPT 10/11-21
Clinical safety rating: caution
Comprehensive clinical and safety monograph for GENCEPT 10/11-21 (GENCEPT 10/11-21).
GENCEPT 10/11-21 is a combination contraceptive vaginal ring containing ethinyl estradiol and etonogestrel. Ethinyl estradiol is an estrogen that suppresses gonadotropin release, inhibiting ovulation. Etonogestrel is a progestin that thickens cervical mucus, inhibiting sperm penetration, and alters the endometrium.
| Metabolism | Ethinyl estradiol is primarily metabolized by CYP3A4 via hydroxylation; etonogestrel is metabolized by CYP3A4 and CYP2C9. |
| Excretion | Renal (30-40% as unchanged drug and metabolites), biliary/fecal (50-60% as metabolites) |
| Half-life | Terminal elimination half-life is 24-30 hours; allows once-daily dosing; steady-state achieved in 5-7 days |
| Protein binding | Ethinyl estradiol: 97-98% bound to albumin; desogestrel: 91-96% bound to SHBG and albumin |
| Volume of Distribution | Ethinyl estradiol: 2.7-3.9 L/kg; desogestrel: 1.5-2.0 L/kg; indicates extensive tissue distribution |
| Bioavailability | Oral: ethinyl estradiol ~45% (first-pass metabolism), desogestrel ~76% (as active metabolite etonogestrel) |
| Onset of Action | Oral: 3-5 days for therapeutic effect (contraception) |
| Duration of Action | Oral: 24 hours (contraceptive coverage); requires daily dosing; missed pills reduce efficacy |
One tablet (10 mg ethinyl estradiol and 11 mg gestodene on days 1-7, then placebo on days 8-21) orally once daily for 21 days, followed by 7 placebo days.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment. Contraindicated in severe renal disease or acute renal failure. |
| Liver impairment | Contraindicated in severe hepatic disease, hepatocellular carcinoma, or active liver disease. Use with caution in mild to moderate impairment; no specific dose recommendations available. |
| Pediatric use | Not indicated for use before menarche. Post-menarche, same dosing as adults: one tablet daily on days 1-21, then 7 placebo days. |
| Geriatric use | Not indicated for use after menopause. No specific dose adjustments in elderly due to lack of use. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for GENCEPT 10/11-21 (GENCEPT 10/11-21).
| Breastfeeding | Small amounts of EE and LNG pass into breast milk. M/P ratio: EE ~0.4, LNG ~0.1. May reduce milk production, especially with high doses. Not recommended during breastfeeding; if used, lowest effective dose and monitor infant for jaundice or growth. Consider alternative contraception. |
| Teratogenic Risk | GENCEPT 10/11-21 contains ethinylestradiol (EE) and levonorgestrel (LNG). EE/LNG is contraindicated during pregnancy. First trimester: Risk of congenital anomalies (e.g., heart defects, limb reduction) from exogenous sex hormones. Second/Third trimester: Increased risk of fetal harm, including genital abnormalities in female fetuses from androgenic effects of progestins. Use should be discontinued immediately if pregnancy occurs. |
■ FDA Black Box Warning
Cigarette smoking increases the risk of serious cardiovascular events from combination hormonal contraceptive use. This risk increases with age, especially in women over 35, and with the number of cigarettes smoked. Women who use combination hormonal contraceptives should be strongly advised not to smoke.
| Serious Effects |
["Hypersensitivity to any component","Thrombophlebitis or thromboembolic disorders","History of deep vein thrombosis or pulmonary embolism","Cerebrovascular or coronary artery disease","Known or suspected pregnancy","Undiagnosed abnormal uterine bleeding","Known or suspected breast cancer","Liver tumor or active liver disease","Uncontrolled hypertension","Diabetes with vascular involvement","Headache with focal neurological symptoms or migraine with aura age ≥35","Major surgery with prolonged immobilization","Renal disease","Adrenal insufficiency"]
| Precautions | ["Thrombotic disorders and cardiovascular events","Liver disease","Hypertension","Gallbladder disease","Carbohydrate and lipid effects","Headache/migraine","Bleeding irregularities","Ectopic pregnancy","Depression","Hereditary angioedema","Chloasma","Ocular effects","Drug interactions"] |
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| Fetal Monitoring | Maternal: Blood pressure (risk of hypertension), liver function (hepatotoxicity), glucose tolerance (insulin resistance), and signs of thromboembolism. Fetal: Ultrasound if exposure occurs, assess for congenital anomalies. No routine monitoring required if used appropriately in non-pregnant women. |
| Fertility Effects | No adverse effects on fertility after discontinuation. Return to normal ovulation typically within 1-3 cycles. Long-term use does not impair future fertility. |