LOESTRIN 21 1.5/30
Clinical safety rating: caution
Comprehensive clinical and safety monograph for LOESTRIN 21 1.5/30 (LOESTRIN 21 1.5/30).
Combination estrogen-progestin contraceptive: suppresses gonadotropin release, inhibiting ovulation; increases viscosity of cervical mucus, impeding sperm penetration; alters endometrial morphology.
| Metabolism | Ethinyl estradiol undergoes CYP3A4-mediated hydroxylation and conjugation; norethindrone undergoes reduction, sulfate conjugation, and CYP3A4 metabolism. |
| Excretion | Primarily hepatic metabolism; ~40-60% renal, 20-30% biliary/fecal. |
| Half-life | Ethinyl estradiol: ~12-14 h; Norethindrone: ~5-12 h. Steady-state achieved in ~5-10 days. |
| Protein binding | Ethinyl estradiol: ~97-98% (albumin); Norethindrone: ~80-90% (SHBG & albumin). |
| Volume of Distribution | Ethinyl estradiol: ~1.2-1.8 L/kg; Norethindrone: ~3.4 L/kg. Suggests extensive tissue distribution. |
| Bioavailability | Oral: Ethinyl estradiol ~38-48%, Norethindrone ~64-71% due to first-pass metabolism. |
| Onset of Action | Oral: 24-48 h for contraceptive effect; requires 7-day continuous dosing for full suppression. |
| Duration of Action | Contraceptive protection for duration of dosing; withdrawal bleed within 2-3 days post-dose. Weekly cyclic schedule required. |
One tablet (norethindrone acetate 1.5 mg/ethinyl estradiol 30 mcg) orally once daily for 21 consecutive days, followed by 7 days off therapy.
| Dosage form | TABLET |
| Renal impairment | No dosage adjustment required for mild-to-moderate renal impairment. Not recommended in patients with severe renal impairment or end-stage renal disease due to limited data. |
| Liver impairment | Contraindicated in patients with acute or chronic hepatic disease, including Child-Pugh class A, B, or C. Do not use. |
| Pediatric use | Safety and efficacy have not been established in postmenarchal adolescents. Use same dosing as adults after menarche if deemed appropriate by clinician; weight-based dosing not applicable. |
| Geriatric use | Not indicated for postmenopausal women. No specific geriatric dosing; avoid use in this population. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for LOESTRIN 21 1.5/30 (LOESTRIN 21 1.5/30).
| Breastfeeding | Small amounts of ethinyl estradiol and norethindrone transfer into breast milk (M/P ratio not established). May reduce milk production and quality, especially with higher doses. Use is generally not recommended during breastfeeding unless benefit outweighs risk. |
| Teratogenic Risk | No increased risk of birth defects based on epidemiological studies; postmarketing reports of congenital anomalies (limb defects, cardiovascular malformations) are rare and lack consistent association. Hormonal effects may cause fetal harm if used inadvertently during pregnancy; pregnancy should be excluded before initiation. Discontinue if pregnancy occurs. |
■ FDA Black Box Warning
Cigarette smoking increases risk of serious cardiovascular events from combined hormonal contraceptive use; risk increases with age and number of cigarettes smoked; women over 35 who smoke should not use this product.
| Serious Effects |
["Known or suspected pregnancy","Current or past thrombophlebitis or thromboembolic disorders","Cerebrovascular or coronary artery disease","Known or suspected carcinoma of the breast or endometrium","Undiagnosed abnormal genital bleeding","Cholestatic jaundice of pregnancy or jaundice with prior pill use","Hepatic adenoma or carcinoma","Known hypersensitivity to any component","Cigarette smoking in women over age 35"]
| Precautions | ["Thrombotic disorders (venous thromboembolism, arterial thromboembolism, stroke, myocardial infarction)","Hypertension","Gallbladder disease","Hepatic neoplasia","Carbohydrate/lipid effects","Headache/migraine","Irregular bleeding/amenorrhea","Drug interactions (e.g., antibiotics, anticonvulsants)","Depression","Retinal thrombosis"] |
Loading safety data…
| Fetal Monitoring | Confirm negative pregnancy test before starting; monitor blood pressure, liver function, and signs of thromboembolism. In pregnant patients inadvertently exposed, no specific fetal monitoring required beyond routine prenatal care. |
| Fertility Effects | Suppresses ovulation via gonadotropin inhibition; after discontinuation, normal ovulatory cycles typically resume within 1-3 months. No evidence of permanent fertility impairment. |