Comparative Pharmacology
Head-to-head clinical analysis: N E E 1 35 21 versus NORLESTRIN 28 1 50.
Peer-Reviewed Evidence
Head-to-head clinical analysis: N E E 1 35 21 versus NORLESTRIN 28 1 50.
N.E.E. 1/35 21 vs NORLESTRIN 28 1/50
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen-progestin contraceptive: ethinyl estradiol (estrogen) and norethindrone (progestin). Suppresses gonadotropin (FSH, LH) release via negative feedback, inhibiting ovulation; increases cervical mucus viscosity to impede sperm penetration; alters endometrial development to reduce implantation likelihood.
Combination estrogen-progestin oral contraceptive; suppresses gonadotropin release via negative feedback on pituitary, inhibits ovulation, thickens cervical mucus, alters endometrial receptivity.
One tablet orally once daily for 21 days, followed by 7 days off.
One tablet orally once daily, each containing norethindrone 1 mg and ethinyl estradiol 50 mcg.
None Documented
None Documented
Norethindrone: terminal half-life 7-8 hours; Ethinyl estradiol: terminal half-life 12-14 hours (with enterohepatic recycling). Clinically, steady state achieved after 5-7 days.
Norethindrone: 8 hours; ethinyl estradiol: 12-15 hours; steady state achieved within 5-10 days.
Norethindrone (NET) and ethinyl estradiol (EE) are excreted primarily in urine (~50-60% as metabolites) and feces (~30-40% as metabolites); less than 1% excreted unchanged.
Norethindrone: 40% renal, 60% fecal; ethinyl estradiol: 40% renal, 60% fecal.
Category C
Category C
Oral Contraceptive
Oral Contraceptive