Comparative Pharmacology
Head-to-head clinical analysis: MICROGESTIN FE 1 20 versus TRI LO ESTARYLLA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MICROGESTIN FE 1 20 versus TRI LO ESTARYLLA.
MICROGESTIN FE 1/20 vs TRI-LO-ESTARYLLA
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 containing ethinyl estradiol and norgestimate. Suppresses gonadotropin secretion, primarily FSH and LH, inhibiting ovulation; increases cervical mucus viscosity, impeding sperm penetration; alters endometrial lining, reducing implantation likelihood.
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 (20 mcg ethinyl estradiol/0.1 mg levonorgestrel) 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
Ethinyl estradiol: 19-24 hours (terminal); Norgestimate: active metabolite norelgestromin 28-38 hours; allows once-daily dosing.
Renal: ~50-60% as metabolites; Fecal: ~30-40% as metabolites; Biliary: minor; <1% unchanged
Renal: ~40% as metabolites; Fecal: ~30% as metabolites (including ethinyl estradiol conjugates); Biliary: ~20% (enterohepatic recirculation).
Category C
Category C
Oral Contraceptive
Oral Contraceptive