Comparative Pharmacology
Head-to-head clinical analysis: LOESTRIN 21 1 5 30 versus LOESTRIN FE 1 5 30.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LOESTRIN 21 1 5 30 versus LOESTRIN FE 1 5 30.
LOESTRIN 21 1.5/30 vs LOESTRIN FE 1.5/30
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen-progestin contraceptive: suppresses gonadotropin release, inhibiting ovulation; increases viscosity of cervical mucus, impeding sperm penetration; alters endometrial morphology.
Suppresses gonadotropin (FSH and LH) release via estrogen and progestin feedback inhibition, preventing ovulation; increases cervical mucus viscosity and alters endometrial lining.
One tablet (norethindrone acetate 1.5 mg/ethinyl estradiol 30 mcg) orally once daily for 21 consecutive days, followed by 7 days off therapy.
One tablet orally once daily at the same time each day for 21 consecutive days, followed by 7 days of placebo (ferrous fumarate) tablets, then restart.
None Documented
None Documented
Ethinyl estradiol: ~12-14 h; Norethindrone: ~5-12 h. Steady-state achieved in ~5-10 days.
Norethindrone: ~5-14 hours (terminal); Ethinyl estradiol: ~13-27 hours (terminal). Clinically, steady-state achieved within 5-7 days.
Primarily hepatic metabolism; ~40-60% renal, 20-30% biliary/fecal.
Renal: ~50-60% (norethindrone metabolites); Fecal: ~20-30% (norethindrone); Ethinyl estradiol: primarily renal (~40-50%) and fecal (~20-50%) as glucuronide and sulfate conjugates.
Category C
Category C
Combined Oral Contraceptive
Combined Oral Contraceptive