MICROGESTIN FE 1.5/30
Clinical safety rating
cautionComprehensive clinical and safety monograph for MICROGESTIN FE 1.5/30 (MICROGESTIN FE 1.5/30).
Combination oral contraceptive: ethinyl estradiol (estrogen) and norethindrone acetate (progestin) suppress gonadotropin (FSH, LH) release, preventing ovulation; increase cervical mucus viscosity, inhibiting sperm penetration; alter endometrial development, reducing implantation likelihood.
| Metabolism | Ethinyl estradiol: primarily metabolized via CYP3A4; undergoes first-pass metabolism in gut and liver. Norethindrone acetate: deacetylated to norethindrone, metabolized mainly via reduction and conjugation (glucuronidation, sulfation), partly by CYP3A4. |
| Excretion | Norethindrone: 50-60% renal (as metabolites), 20-40% fecal; Ethinyl estradiol: ~40% renal, ~60% fecal (as glucuronide/sulfate conjugates). |
| Half-life | Norethindrone: 6-8 hours (terminal); Ethinyl estradiol: 12-18 hours (terminal). Clinical context: Steady-state achieved within 5-7 days; dosing interval suitable for once-daily administration. |
| Protein binding | Norethindrone: ~97% albumin and SHBG; Ethinyl estradiol: ~98% albumin (induces SHBG synthesis). |
| Volume of Distribution | Norethindrone: 2-5 L/kg (wide distribution, including breast tissue and adipose); Ethinyl estradiol: 2-4 L/kg (extensive distribution into reproductive tissues). |
| Bioavailability | Norethindrone: ~64% (oral, first-pass metabolism); Ethinyl estradiol: ~40-45% (oral, first-pass metabolism). |
| Onset of Action | Oral: 24-48 hours for contraceptive effect via suppression of ovulation (requires 7 consecutive days for full hypothalamic-pituitary-ovarian axis suppression). |
| Duration of Action | 24 hours (contraceptive efficacy maintained with daily dosing; breakthrough bleeding risk if dose missed >12 hours). |
| Molecular Weight | 340.46 |
| Action Class | Oral Contraceptive; Estrogen-Progestin Combination |
One tablet (norethindrone acetate 1.5 mg, ethinyl estradiol 30 mcg) orally once daily for 28-day cycles (21 active tablets + 7 ferrous fumarate tablets).
| Dosage form | TABLET |
| Renal impairment | No dose adjustment required for mild to moderate renal impairment (eGFR ≥30 mL/min/1.73 m²). Not recommended in severe impairment (eGFR <30 mL/min/1.73 m²) due to limited data. |
| Liver impairment | Contraindicated in Child-Pugh class B or C (moderate to severe hepatic impairment). For Child-Pugh class A (mild impairment), use with caution; no specific dose adjustment established, but may increase risk of adverse effects. |
| Pediatric use | Approved for postmenarcheal adolescents. Dose same as adults: one tablet orally once daily for 28-day cycles. Not indicated for premenarcheal patients. |
| Geriatric use | Not indicated for use in women over 65 years due to lack of efficacy and safety data; increased risk of thromboembolic events and cardiovascular disease outweighs potential benefit. |
| 1st trimester | Contraindicated due to risk of fetal harm; oral contraceptive use in early pregnancy may be associated with congenital anomalies. |
| 2nd trimester | Contraindicated; may cause fetal harm and is not indicated during pregnancy. |
| 3rd trimester | Contraindicated; may cause fetal harm and is not indicated during pregnancy. |
Clinical note
Comprehensive clinical and safety monograph for MICROGESTIN FE 1.5/30 (MICROGESTIN FE 1.5/30).
| Placental transfer | Ethinyl estradiol and norethindrone cross the placenta; fetal plasma concentrations may reach clinically relevant levels. |
| Breastfeeding | Combined hormonal contraceptives may reduce milk production and are not recommended for breastfeeding women, especially during the first 6 weeks postpartum. Small amounts pass into breast milk but no adverse effects reported in infants. |
| Lactation Rating | L3 - Moderately Safe |
| Teratogenic Risk | FDA Pregnancy Category X. First trimester: No increased risk of major birth defects from inadvertent use, but post-fertilization effects are theoretical. Contraindicated in pregnancy due to estrogen component and progestin exposure. Second/third trimester: Irrelevant as drug is contraindicated; no fetal exposure studies. Use in pregnancy may cause fetal harm: possible congenital anomalies (limb defects, heart defects) and adverse outcomes (low birth weight, premature birth, neonatal withdrawal) with prolonged exposure. |
| Fetal Monitoring | If inadvertently used during pregnancy, discontinue immediately. Perform ultrasound for fetal anatomy and growth monitoring. No routine monitoring required in non-pregnant women; however, in women of reproductive potential, ensure pregnancy test prior to initiation and monthly monitoring of blood pressure, weight, and adverse effects. Consider liver function tests if symptoms of hepatic impairment. |
| Fertility Effects | Suppresses ovulation via negative feedback on gonadotropins. Returns to normal ovulation within 1-2 cycles after discontinuation. No permanent negative impact on fertility; can be used for cycle regulation. Reversible impairment of fertility due to anovulation while on therapy. |
■ 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 >=35 who smoke should not use this product.
| Common Effects | Nausea, Headache, Breast tenderness, Weight changes, Irregular uterine bleeding, Mood changes |
| Serious Effects | Venous thromboembolism (deep vein thrombosis, pulmonary embolism), Arterial thromboembolism (myocardial infarction, stroke), Hepatic adenoma or hepatocellular carcinoma, Hypertension, Gallbladder disease, Cerebral hemorrhage |
Thrombophlebitis or thromboembolic disordersHistory of deep vein thrombosis or pulmonary embolismCerebrovascular or coronary artery diseaseKnown or suspected breast cancerEstrogen-dependent neoplasiaUndiagnosed abnormal genital bleedingCholestatic jaundice of pregnancy or jaundice with prior pill useHepatic adenoma or carcinomaKnown or suspected pregnancy
| Precautions | Thrombotic disorders (venous thromboembolism, arterial thrombosis, stroke, MI), Carcinoma of breast/cervix, Hepatic disease (jaundice, tumors), Elevated blood pressure, Gallbladder disease, Carbohydrate/lipid effects, Headache/migraine, Vaginal bleeding irregularities, Depression, Hereditary angioedema, Chloasma, Pregnancy loss |
| Food/Dietary | No significant food interactions. Grapefruit juice may increase estrogen levels but no specific restriction is required. Iron tablets should be taken on an empty stomach for best absorption, but can be taken with food if GI upset occurs. |
| Clinical Pearls | MICROGESTIN FE 1.5/30 contains norethindrone acetate 1.5 mg and ethinyl estradiol 30 mcg, plus ferrous fumarate (iron) tablets. The iron tablets are not part of the contraceptive regimen and should be taken only if iron deficiency is a concern. Because it is a combination oral contraceptive (COC), it has higher estrogen content compared to low-dose pills, which may increase the risk of thromboembolism. It is indicated for contraception and may also be used for menstrual disorders. The ring in the package is a placebo indicator; be aware that patients may confuse the iron tablets for active pills. |
| Patient Advice | Take one active pill at the same time each day, followed by the brown iron tablets during the last 7 days of the pack. · If you miss a dose, follow the package instructions: take the missed pill as soon as remembered, and use backup contraception if more than one pill is missed. · Smoking increases the risk of serious cardiovascular side effects from birth control pills, especially if you are over 35. · Common side effects include nausea, breast tenderness, and breakthrough bleeding, which often resolve within a few months. · This pill does not protect against HIV or other sexually transmitted infections. |
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