Comparative Pharmacology
Head-to-head clinical analysis: MICROGESTIN FE 1 20 versus OGESTREL 0 5 50 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MICROGESTIN FE 1 20 versus OGESTREL 0 5 50 28.
MICROGESTIN FE 1/20 vs OGESTREL 0.5/50-28
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 contraceptive; suppresses gonadotropins (FSH, LH) via negative feedback on hypothalamic-pituitary axis, inhibiting ovulation; increases cervical mucus viscosity and 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 (norgestrel 0.5 mg/ethinyl estradiol 50 mcg) orally once daily for 28-day cycle.
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
Norgestrel: ~45 hours (range 24-56 h) enabling once-daily dosing; Ethinyl estradiol: ~17 hours (range 10-27 h).
Renal: ~50-60% as metabolites; Fecal: ~30-40% as metabolites; Biliary: minor; <1% unchanged
Renal: 50-60% as metabolites (glucuronide and sulfate conjugates of norgestrel and ethinyl estradiol); Fecal: 30-40% via biliary elimination; Unchanged drug: <1%.
Category C
Category C
Oral Contraceptive
Oral Contraceptive