Comparative Pharmacology
Head-to-head clinical analysis: MICROGESTIN FE 1 20 versus TRI LO MILI.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MICROGESTIN FE 1 20 versus TRI LO MILI.
MICROGESTIN FE 1/20 vs TRI-LO-MILI
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 oral contraceptive: ethinyl estradiol suppresses gonadotropin release via negative feedback on the hypothalamic-pituitary axis; norgestimate binds to progesterone receptors, inhibiting ovulation and altering cervical mucus and 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 for 21 days, followed by 7 days of placebo.
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
Terminal elimination half-life: 20-24 hours; allows once-daily dosing for contraceptive efficacy.
Renal: ~50-60% as metabolites; Fecal: ~30-40% as metabolites; Biliary: minor; <1% unchanged
Renal: approximately 50% as metabolites; biliary/fecal: approximately 40% as metabolites; 10% unchanged in urine.
Category C
Category C
Oral Contraceptive
Oral Contraceptive