Comparative Pharmacology
Head-to-head clinical analysis: NORCEPT E 1 35 28 versus NORINYL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: NORCEPT E 1 35 28 versus NORINYL.
NORCEPT-E 1/35 28 vs NORINYL
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen (ethinyl estradiol) and progestin (norethindrone) contraceptive: suppresses gonadotropin release, inhibits ovulation, thickens cervical mucus, and alters endometrial lining.
Combination of norethindrone (progestin) and ethinyl estradiol (estrogen) provides contraception by inhibiting gonadotropin secretion via negative feedback on the hypothalamic-pituitary-ovarian axis, suppressing ovulation, increasing cervical mucus viscosity, and altering endometrial receptivity.
1 tablet orally once daily for 21 days, followed by 7 days of placebo tablets.
One tablet (norethindrone 1 mg/ethinyl estradiol 0.035 mg) orally once daily for 21 days, followed by 7 placebo tablets. For first cycle, start on first Sunday after menstruation begins or on day 1 of menstrual cycle.
None Documented
None Documented
Norethindrone: 5-14 hours; ethinyl estradiol: 13-27 hours. The terminal half-life of norethindrone is about 10 hours, allowing once-daily dosing; ethinyl estradiol's longer half-life contributes to steady-state concentrations within 3-5 days.
Terminal half-life: norethindrone 7-8 hours, ethinyl estradiol 13-27 hours; clinical context: steady-state achieved in 3-5 half-lives
Renal (primarily as metabolites) and fecal; approximately 50-60% excreted in urine, 30-40% in feces. Ethinyl estradiol and norethindrone are extensively metabolized via hydroxylation and conjugation; glucuronide and sulfate conjugates are eliminated in urine and bile.
Renal: ~60% as metabolites, biliary/fecal: ~40% as glucuronide conjugates
Category C
Category C
Combined Oral Contraceptive
Combined Oral Contraceptive