Comparative Pharmacology
Head-to-head clinical analysis: NORLESTRIN FE 1 50 versus TRI LEGEST FE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORLESTRIN FE 1 50 versus TRI LEGEST FE.
NORLESTRIN FE 1/50 vs TRI-LEGEST FE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination of ethinyl estradiol and norethindrone acetate provides negative feedback on gonadotropin release, suppressing ovulation. Also causes cervical mucus thickening and endometrial thinning.
Tri-Legest FE is a combination oral contraceptive containing ethinyl estradiol and norethindrone acetate. It prevents ovulation by inhibiting gonadotropin release (FSH and LH) and alters cervical mucus and endometrial lining to impede sperm penetration and implantation.
One tablet (norethindrone 1 mg and ethinyl estradiol 50 mcg plus ferrous fumarate 75 mg) orally once daily for 28 days, with 21 active tablets and 7 placebo tablets.
One tablet orally once daily for 28-day cycle: 21 days active tablets (norethindrone/ethinyl estradiol) followed by 7 days placebo. For contraception only.
None Documented
None Documented
Norethindrone: 5-12 hours (mean 8 hours). Ethinyl estradiol: 11-16 hours. Clinical context: Steady state reached in 5-7 days.
Norethindrone: 7-8 hours; Ethinyl estradiol: 18 hours (terminal). Steady-state reached after 7 days; clinical contraceptive efficacy requires consistent dosing.
Norethindrone: 20% renal, 80% fecal. Ethinyl estradiol: 40% renal, 60% fecal.
Renal: ~60% (metabolites), Fecal: ~30% (metabolites), Biliary: minor (~5% as conjugates)
Category C
Category C
Oral Contraceptive
Oral Contraceptive