OGESTREL 0.5/50-21
Clinical safety rating: caution
Comprehensive clinical and safety monograph for OGESTREL 0.5/50-21 (OGESTREL 0.5/50-21).
Combination of norgestrel and ethinyl estradiol suppresses gonadotropin release, inhibiting ovulation; alters cervical mucus and endometrial lining.
| Metabolism | Hepatic, via CYP3A4; norgestrel undergoes reduction, conjugation; ethinyl estradiol is metabolized by CYP3A4 and undergoes glucuronidation. |
| Excretion | Renal: ~50% (metabolites); Fecal/Biliary: ~50% (metabolites); <1% unchanged in urine. |
| Half-life | Norgestrel: 24-32 hours; Ethinyl estradiol: 7-12 hours. Clinical context: Steady state achieved after 5-7 days. |
| Protein binding | Norgestrel: 93-95% to albumin and SHBG; Ethinyl estradiol: 97-98% to albumin. |
| Volume of Distribution | Norgestrel: 2.5-3.5 L/kg; Ethinyl estradiol: 2.5-4 L/kg. Indicates extensive tissue distribution. |
| Bioavailability | Oral: Norgestrel ~95%; Ethinyl estradiol ~40-60% due to first-pass metabolism. |
| Onset of Action | Oral: Maximal contraceptive effect within 7 days if started on day 1 of menses. |
| Duration of Action | Oral: Duration of contraceptive effect with daily dosing; missed pills increase pregnancy risk. |
One tablet (norgestrel 0.5 mg / ethinyl estradiol 0.05 mg) 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 due to potential fluid retention. |
| Liver impairment | Contraindicated in acute or chronic hepatic disease; do not use in Child-Pugh class B or C. Use with caution in mild impairment (Child-Pugh A) at minimal effective dose. |
| Pediatric use | Not indicated for use before menarche. For postmenarchal adolescents, same dosing as adults (one tablet daily for 21 days). |
| Geriatric use | Not indicated for use after menopause. In elderly patients, evaluate cardiovascular and hepatic status; consider lower estrogen dose if necessary. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for OGESTREL 0.5/50-21 (OGESTREL 0.5/50-21).
| Breastfeeding | Excreted in breast milk; may reduce milk production and composition. M/P ratio not established. Use not recommended in nursing mothers. |
| Teratogenic Risk | Pregnancy category X. Contraindicated in pregnancy due to known teratogenicity. First trimester: limb defects, cardiac anomalies; second/third trimester: feminization of male fetus, urogenital abnormalities. |
| Fetal Monitoring |
■ FDA Black Box Warning
Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptives; risk increases with age and heavy smoking (≥15 cigarettes/day); women over 35 who smoke should not use this product.
| Serious Effects |
Thrombophlebitis or thromboembolic disorders; cerebrovascular or coronary artery disease; known or suspected carcinoma of the breast; carcinoma of the endometrium or other estrogen-dependent neoplasia; undiagnosed abnormal genital bleeding; pregnancy; jaundice with prior pill use; hepatic adenoma or carcinoma; age >35 and smoking ≥15 cigarettes/day.
| Precautions | Increased risk of thromboembolic disorders; hepatic neoplasia; elevated blood pressure; gallbladder disease; carbohydrate and lipid metabolism effects; breakthrough bleeding and spotting; use in pregnancy; depression; contact lens intolerance; fluid retention; hereditary angioedema. |
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| Monitor for thromboembolism, hypertension, glucose intolerance, hepatic dysfunction. Ultrasound if inadvertent use in early pregnancy. |
| Fertility Effects | Suppresses ovulation. Reversible after discontinuation; no long-term effect on fertility. |