Comparative Pharmacology
Head-to-head clinical analysis: NORLESTRIN 28 1 50 versus NORTREL 0 5 35 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORLESTRIN 28 1 50 versus NORTREL 0 5 35 28.
NORLESTRIN 28 1/50 vs NORTREL 0.5/35-28
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.
Norethindrone and ethinyl estradiol are a combination hormonal contraceptive. Norethindrone suppresses gonadotropin release (FSH and LH) from the pituitary, inhibiting ovulation. Ethinyl estradiol stabilizes the endometrium and enhances the contraceptive effect by inhibiting gonadotropin secretion.
One tablet orally once daily, each containing norethindrone 1 mg and ethinyl estradiol 50 mcg.
1 tablet orally once daily for 28 days (21 active tablets containing 0.5 mg norethindrone and 35 mcg ethinyl estradiol, followed by 7 placebo tablets).
None Documented
None Documented
Norethindrone: 8 hours; ethinyl estradiol: 12-15 hours; steady state achieved within 5-10 days.
Norethindrone: 7.2-9.2 hours; Ethinyl estradiol: 13-27 hours. Clinical context: Steady state reached in 5-7 days; half-life supports once-daily dosing.
Norethindrone: 40% renal, 60% fecal; ethinyl estradiol: 40% renal, 60% fecal.
Renal: ~40% as metabolites; Biliary/Fecal: ~60% as metabolites; <5% unchanged.
Category C
Category C
Oral Contraceptive
Oral Contraceptive