OVCON-50
Clinical safety rating
cautionComprehensive clinical and safety monograph for OVCON-50 (OVCON-50).
Combination estrogen-progestin contraceptive; suppresses gonadotropin release, inhibiting ovulation, and alters cervical mucus and endometrial lining.
| Metabolism | Hepatic; ethinyl estradiol via CYP3A4; norethindrone via reduction and conjugation. |
| Excretion | Renal: 40-60% (metabolites, primarily glucuronide conjugates; <1% unchanged). Fecal: 30-50% (via biliary elimination). |
| Half-life | Norethindrone: 5-14 hours (terminal); ethinyl estradiol: 7-20 hours. Clinical context: Steady-state reached within 5-7 days; half-life allows once-daily dosing with stable contraceptive efficacy. |
| Protein binding | Norethindrone: 95-97% (mainly albumin, 35% SHBG); ethinyl estradiol: 97-99% (mainly albumin). |
| Volume of Distribution | Norethindrone: 2-4 L/kg; ethinyl estradiol: 1.5-3 L/kg. Indicates extensive tissue distribution, including breast, uterus, and hypothalamus. |
| Bioavailability | Oral: Norethindrone 60-70%; ethinyl estradiol 40-50% (first-pass metabolism; CYP3A4 and conjugation). |
| Onset of Action | Oral: 7 days of consecutive dosing required for full contraceptive effect; immediate if started within first 5 days of menstrual cycle. |
| Duration of Action | 24 hours (supports once-daily dosing). Missed dose guidelines apply beyond 24 hours; contraceptive failure risk increases with extended noncompliance. |
| Molecular Weight | 340.46 |
One tablet (norethindrone 1 mg and ethinyl estradiol 50 mcg) orally once daily for 21 days followed by 7 days of placebo or no tablets.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment. Limited data in severe impairment; use with caution and monitor for fluid retention. |
| Liver impairment | Contraindicated in Child-Pugh class B and C (severe hepatic impairment). Use with caution in class A; consider alternative therapy due to potential metabolic impairment. |
| Pediatric use | Not indicated for use before menarche. Post-menarche: same adult dosing (one tablet daily). |
| Geriatric use | Not indicated for postmenopausal women; if used, consider increased risk of thromboembolic events and cardiovascular disease. No specific dose adjustment, but use lowest effective dose if necessary. |
| 1st trimester | Contraindicated in first trimester due to risk of fetal harm, including cardiovascular and neural tube defects, from estrogen and progestogen exposure. |
| 2nd trimester | Risk of fetal harm, including potential for urogenital abnormalities and other malformations, especially with prolonged use. Use only if clearly needed and no alternative. |
| 3rd trimester | Risk of fetal harm, including potential for feminization of male fetuses and other adverse effects. Use only if clearly needed and no alternative. |
Clinical note
Comprehensive clinical and safety monograph for OVCON-50 (OVCON-50).
| Placental transfer | Significant placental transfer; both ethinyl estradiol and norethindrone cross the placenta, with fetal concentrations approximately 50% of maternal levels. |
| Breastfeeding | Excreted in breast milk; may reduce milk production and affect infant development. Use alternative contraception during breastfeeding. If indicated, monitor infant for jaundice, breast enlargement, and other hormonal effects. |
| Lactation Rating | L4 (Possibly Hazardous) |
| Teratogenic Risk | Pregnancy Category X. First trimester: Use contraindicated due to risk of congenital anomalies, including cardiovascular and limb defects. Second and third trimesters: Associated with fetal harm (e.g., genital abnormalities in females, feminization of male fetuses) and increased risk of fetal loss. Contraindicated throughout pregnancy. |
| Fetal Monitoring | Monitor for pregnancy status (rule out pregnancy before initiation). If inadvertent exposure occurs, monitor fetal development via ultrasound. Assess for thromboembolic events in mother. No routine fetal monitoring required if contraindicated. |
| Fertility Effects | Reversible suppression of ovulation. After discontinuation, fertility typically returns within 1-3 cycles. No permanent negative impact on fertility. |
■ FDA Black Box Warning
Cigarette smoking increases risk of serious cardiovascular events; contraindicated in women over 35 who smoke.
| Serious Effects |
PregnancyKnown or suspected estrogen-dependent neoplasiaHistory of thromboembolic disordersActive liver disease or impaired liver functionUndiagnosed abnormal genital bleedingHypersensitivity to any component
| Precautions | Increased risk of thromboembolic disorders, Cardiovascular disease risk in smokers, Hepatic neoplasia, Gallbladder disease, Hypertension |
| Food/Dietary | No significant food interactions. Grapefruit juice may increase ethinyl estradiol levels; avoid excessive consumption. Maintain consistent diet to avoid GI upset that could affect absorption. |
| Clinical Pearls | OVCON-50 is a combined oral contraceptive containing norethindrone 1 mg and ethinyl estradiol 50 mcg. Monitor for thromboembolic events, especially in smokers over 35. Counsel on missed dose protocol: take as soon as remembered; if >24 hours late, use backup contraception for 7 days. Note potential for reduced efficacy with enzyme-inducing drugs (e.g., rifampin, barbiturates). |
| Patient Advice | Take one tablet daily at the same time each day. · If you miss a dose, take it as soon as you remember; if more than 24 hours late, use backup contraception for 7 days. · Avoid smoking, especially if over age 35, due to increased risk of blood clots. · Report symptoms of thromboembolism: sudden chest pain, shortness of breath, leg pain/swelling, or visual disturbances. · This medication does not protect against STDs or HIV. · Consult doctor before starting any new medications or supplements. |
Loading safety data…