LOW-OGESTREL-28
Clinical safety rating
cautionComprehensive clinical and safety monograph for LOW-OGESTREL-28 (LOW-OGESTREL-28).
Combination oral contraceptive: ethinyl estradiol and norgestrel inhibit ovulation via suppression of gonadotropins (LH, FSH); increase viscosity of cervical mucus, impairing sperm penetration; alter endometrial structure, reducing implantation likelihood.
| Metabolism | Ethinyl estradiol: metabolized via CYP3A4, undergoes first-pass metabolism, conjugates with sulfate and glucuronide. Norgestrel: primarily metabolized via reduction, hydroxylation, and conjugation; CYP3A4 involved. |
| Excretion | Renal 50-60% as metabolites, fecal 40-50% via biliary elimination. Ethinyl estradiol undergoes enterohepatic recirculation. |
| Half-life | Norgestrel: ~45 hours (terminal). Ethinyl estradiol: ~13 hours (terminal). Steady-state achieved within 5-7 days. |
| Protein binding | Norgestrel: 97-99% bound to SHBG and albumin. Ethinyl estradiol: 98% bound to albumin. |
| Volume of Distribution | Norgestrel: 3-4 L/kg (extensive tissue distribution). Ethinyl estradiol: 3-5 L/kg. |
| Bioavailability | Norgestrel: ~90% oral (first-pass metabolism minimal). Ethinyl estradiol: ~45% oral (extensive first-pass metabolism). |
| Onset of Action | Oral: 7 days of continuous dosing required for full contraceptive effect; ovulation inhibition begins after first dose. |
| Duration of Action | Contraceptive protection lasts 24 hours with daily dosing; missed pills reduce efficacy. Withdrawal bleed occurs during placebo week. |
| Molecular Weight | Ethinyl estradiol: 296.4 Da; Norgestrel: 312.4 Da |
One tablet (norgestrel 0.3 mg/ethinyl estradiol 30 mcg) orally once daily at the same time each day for 28 days, with 21 active tablets followed by 7 inactive tablets.
| Dosage form | TABLET |
| Renal impairment | No dosage adjustment required for mild to moderate renal impairment. Insufficient data for severe impairment (CrCl <30 mL/min); use with caution. |
| Liver impairment | Contraindicated in severe hepatic disease or liver tumors (Child-Pugh class C). For mild to moderate impairment (Child-Pugh A or B), use with caution and monitor liver function; no specific dose adjustment established. |
| Pediatric use | Not indicated for premenarchal patients. Postmenarchal adolescents: same as adult dose (one tablet daily) after menarche. |
| Geriatric use | Not indicated for postmenopausal women due to lack of contraceptive need and potential increased risks of thrombosis, cardiovascular events, and malignancies. |
| 1st trimester | Contraindicated due to risk of congenital anomalies (oral clefts, cardiac defects) and potential masculinization of female fetus. |
| 2nd trimester | Contraindicated due to risk of fetal harm; alternative contraception recommended. |
| 3rd trimester | Contraindicated due to possible estrogenic effects on fetus and risk of withdrawal bleeding in neonates. |
Clinical note
Comprehensive clinical and safety monograph for LOW-OGESTREL-28 (LOW-OGESTREL-28).
| Placental transfer | Low molecular weight and lipophilicity allow placental transfer; ethinyl estradiol and norgestrel are detected in fetal circulation. |
| Breastfeeding | Estrogens and progestins are excreted in breast milk in small amounts, potentially reducing milk production and quality. Use only if clearly needed; consider alternative non-hormonal contraception during lactation. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | First trimester: Low risk of major malformations; no evidence of increased risk of neural tube defects. Second and third trimesters: Possible increased risk of liver tumors and jaundice; may cause fetal harm if administered during pregnancy due to hormonal effects. Post-marketing reports of external genitalia anomalies in male and female fetuses exposed to progestins. Not recommended for use during pregnancy. Discontinue if pregnancy occurs. |
| Fetal Monitoring | Monitor blood pressure, liver function, glucose tolerance, and lipid profile. Rule out pregnancy before initiating therapy. Perform pregnancy test if pregnancy is suspected. Monitor for signs of thromboembolism. For fetal monitoring, consider ultrasound if prolonged use during gestation. |
| Fertility Effects | Suppresses ovulation; fertility returns rapidly after discontinuation. No permanent adverse effects on fertility. Approved for oral contraception. |
■ FDA Black Box Warning
Cigarette smoking increases risk of serious cardiovascular events from combination oral contraceptive use. Risk increases with age and heavy smoking (≥15 cigarettes/day) and is significant in women over 35. Women who use combination hormonal contraceptives should be strongly advised not to smoke.
| Serious Effects |
Known or suspected pregnancyHistory of thromboembolic disordersCerebrovascular or coronary artery diseaseKnown or suspected breast carcinomaUndiagnosed abnormal genital bleedingHepatic adenoma or carcinomaActive liver disease with abnormal liver function
| Precautions | Thrombotic events (e.g., DVT, PE, stroke, MI); hepatic neoplasia; elevated blood pressure; gallbladder disease; carbohydrate and lipid metabolism effects; headache; uterine bleeding irregularities; ectopic pregnancy risk; reduced efficacy with hepatic impairment; monitoring for hypertension, hyperlipidemia, and glucose intolerance. |
| Food/Dietary | No significant food interactions. Grapefruit juice may increase ethinyl estradiol levels due to CYP3A4 inhibition, but clinical significance is minimal. Maintain consistent dietary habits regarding grapefruit consumption to avoid fluctuation in drug levels. Alcohol does not directly affect efficacy but may impair judgment regarding compliance. |
| Clinical Pearls | Low-Ogestrel-28 (norgestrel/ethinyl estradiol) is a monophasic oral contraceptive. Take at the same time daily to maintain hormone levels. Missed pill management: if one pill is missed, take it as soon as remembered; if two or more pills are missed, use backup contraception for 7 days. Consider potential drug interactions with CYP3A4 inducers (e.g., rifampin, certain anticonvulsants) which may reduce efficacy. Breakthrough bleeding is common in first 3 months; if persistent, rule out pregnancy or cervical pathology. Do not use in patients with history of thromboembolic disease, migraines with aura, or smokers >35 years old. |
| Patient Advice | Take one pill daily at the same time, even if you do not have intercourse. · If you miss a pill, refer to the packaging instructions or contact your healthcare provider. · Use a backup method (e.g., condoms) during the first week and if doses are missed. · Common side effects include nausea, breast tenderness, breakthrough bleeding, and mood changes; these often improve after 3 months. · Serious risks include blood clots, stroke, and liver tumors; seek medical help for leg pain, chest pain, severe headache, or vision changes. · Do not smoke while taking this medication, especially if over 35 years old. · Inform all healthcare providers that you are taking this contraceptive. · This medication does not protect against HIV or other sexually transmitted infections. |
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