Comparative Pharmacology
Head-to-head clinical analysis: MICROGESTIN FE 1 20 versus NORLESTRIN 28 1 50.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MICROGESTIN FE 1 20 versus NORLESTRIN 28 1 50.
MICROGESTIN FE 1/20 vs NORLESTRIN 28 1/50
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; suppresses gonadotropin release via negative feedback on pituitary, inhibits ovulation, thickens cervical mucus, alters endometrial receptivity.
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 orally once daily, each containing norethindrone 1 mg and ethinyl estradiol 50 mcg.
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
Norethindrone: 8 hours; ethinyl estradiol: 12-15 hours; steady state achieved within 5-10 days.
Renal: ~50-60% as metabolites; Fecal: ~30-40% as metabolites; Biliary: minor; <1% unchanged
Norethindrone: 40% renal, 60% fecal; ethinyl estradiol: 40% renal, 60% fecal.
Category C
Category C
Oral Contraceptive
Oral Contraceptive