Comparative Pharmacology
Head-to-head clinical analysis: MICROGESTIN FE 1 20 versus OVULEN 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MICROGESTIN FE 1 20 versus OVULEN 21.
MICROGESTIN FE 1/20 vs OVULEN-21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive containing ethinyl estradiol (estrogen) and norethindrone acetate (progestin). Suppresses gonadotropins via negative feedback on hypothalamic-pituitary axis, inhibiting ovulation; increases cervical mucus viscosity and alters endometrial lining.
Combination estrogen-progestin oral contraceptive; inhibits gonadotropin release, suppressing ovulation; increases viscosity of cervical mucus, impeding sperm penetration; alters endometrial development.
One tablet orally once daily, containing norethindrone acetate 1 mg and ethinyl estradiol 20 mcg, taken at the same time each day for 21 days followed by 7 days of placebo (iron tablets) or continuous cycling per prescribing information.
One tablet (ethinyl estradiol 0.05 mg and norethindrone 1 mg) orally once daily for 21 consecutive days, followed by 7 days without medication.
None Documented
None Documented
Norethindrone: 5-14 hours (mean 8 hours); Ethinyl estradiol: 12-24 hours (mean 18 hours); Steady-state in 5-7 days
Ethinyl estradiol: 13-27 hours (mean ~17 hours); norethindrone: 5-14 hours (mean ~8 hours); terminal half-life supports once-daily dosing.
Renal: ~50-60% as metabolites; Fecal: ~30-40% as metabolites; Biliary: minor; <1% unchanged
Renal: 50-60% as metabolites; fecal: 30-40% as conjugates; biliary excretion significant.
Category C
Category C
Oral Contraceptive
Oral Contraceptive