Comparative Pharmacology
Head-to-head clinical analysis: LESSINA 28 versus NORINYL 1 50 28 DAY.
Peer-Reviewed Evidence
Head-to-head clinical analysis: LESSINA 28 versus NORINYL 1 50 28 DAY.
LESSINA-28 vs NORINYL 1+50 28-DAY
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination of a progestin (levonorgestrel) and an estrogen (ethinyl estradiol). Inhibits ovulation by suppressing gonadotropin release; increases cervical mucus viscosity to impede sperm penetration, and induces endometrial changes that reduce implantation likelihood.
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 (0.1 mg levonorgestrel and 0.02 mg ethinyl estradiol) orally once daily for 28 days, starting on the first day of menstrual cycle.
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
Terminal elimination half-life: 18-22 hours; clinically relevant for once-daily dosing.
Norethindrone: ~8-11 hours; Mestranol: 24 hours (prodrug, ethinyl estradiol half-life ~13-27 hours).
Renal: 30% as unchanged drug and metabolites; biliary/fecal: 70% as metabolites.
Renal: ~40% as metabolites; Biliary/Fecal: ~60% as metabolites.
Category C
Category C
Oral Contraceptive
Oral Contraceptive