Comparative Pharmacology
Head-to-head clinical analysis: N E E 1 35 28 versus NORINYL 1 50 28 DAY.
Peer-Reviewed Evidence
Head-to-head clinical analysis: N E E 1 35 28 versus NORINYL 1 50 28 DAY.
N.E.E. 1/35 28 vs NORINYL 1+50 28-DAY
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination oral contraceptive; ethinyl estradiol and norethindrone suppress gonadotropin (FSH and LH) release, preventing ovulation. Also cause cervical mucus thickening and endometrial changes.
Norethindrone and ethinyl estradiol combination works by suppressing gonadotropin-releasing hormone (GnRH) from the hypothalamus, reducing luteinizing hormone (LH) and follicle-stimulating hormone (FSH) secretion, thereby inhibiting ovulation. Norethindrone also alters cervical mucus viscosity and endometrial lining, impeding sperm penetration and implantation.
One tablet orally once daily for 28 days; each tablet contains norethindrone 1 mg and ethinyl estradiol 35 mcg.
One tablet orally once daily for 28 days, with 7 inactive tablets during the last 7 days. Each active tablet contains norethindrone 1 mg and ethinyl estradiol 50 mcg.
None Documented
None Documented
Ethinyl estradiol: ~15-19 hours (linear pharmacokinetics); Norethindrone: ~7-9 hours (terminal half-life; steady-state achieved within 5-7 days)
Norethindrone: ~8-11 hours; Mestranol: 24 hours (prodrug, ethinyl estradiol half-life ~13-27 hours).
Renal: ~50-60% (metabolites, primarily glucuronide conjugates); Fecal: ~30-40% (biliary excretion of metabolites); Unchanged drug: <5%
Renal: ~40% as metabolites; Biliary/Fecal: ~60% as metabolites.
Category C
Category C
Oral Contraceptive
Oral Contraceptive