Comparative Pharmacology
Head-to-head clinical analysis: NORLESTRIN 28 1 50 versus TRI LEGEST 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORLESTRIN 28 1 50 versus TRI LEGEST 21.
NORLESTRIN 28 1/50 vs TRI-LEGEST 21
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen-progestin oral contraceptive; suppresses gonadotropin release via negative feedback on pituitary, inhibits ovulation, thickens cervical mucus, alters endometrial receptivity.
Combination estrogen-progestin contraceptive; suppresses gonadotropins (FSH, LH), inhibits ovulation, alters cervical mucus and endometrium.
One tablet orally once daily, each containing norethindrone 1 mg and ethinyl estradiol 50 mcg.
One tablet orally once daily for 21 days, followed by 7 tablet-free days. Each tablet contains norgestimate 0.18 mg/ethinyl estradiol 0.025 mg (days 1-7), norgestimate 0.215 mg/ethinyl estradiol 0.025 mg (days 8-14), norgestimate 0.25 mg/ethinyl estradiol 0.025 mg (days 15-21).
None Documented
None Documented
Norethindrone: 8 hours; ethinyl estradiol: 12-15 hours; steady state achieved within 5-10 days.
Ethinyl estradiol: 13-27 hours (mean ~17 hours); norgestimate active metabolite (norelgestromin): 22-36 hours (mean ~28 hours). Steady-state achieved within 5-10 days.
Norethindrone: 40% renal, 60% fecal; ethinyl estradiol: 40% renal, 60% fecal.
Renal: approximately 50-60% as metabolites; fecal: approximately 40-50% (ethinyl estradiol and norgestimate metabolites excreted in bile and feces); less than 1% unchanged in urine.
Category C
Category C
Oral Contraceptive
Oral Contraceptive