Comparative Pharmacology
Head-to-head clinical analysis: ENOVID E versus NORTREL 7 7 7.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ENOVID E versus NORTREL 7 7 7.
ENOVID-E vs NORTREL 7/7/7
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen-progestin contraceptive. Suppresses gonadotropin release, inhibits ovulation, increases cervical mucus viscosity, and alters endometrial morphology.
Combination estrogen-progestin oral contraceptive. Suppresses gonadotropin release, inhibiting ovulation. Increases cervical mucus viscosity and alters endometrial receptivity.
5 mg orally once daily for 20 days starting on day 5 of menstrual cycle
One tablet orally once daily, taken at the same time each day. Each tablet contains norethindrone 0.5 mg/ethinyl estradiol 35 mcg for days 1-7, norethindrone 0.75 mg/ethinyl estradiol 35 mcg for days 8-14, and norethindrone 1 mg/ethinyl estradiol 35 mcg for days 15-21, followed by 7 placebo tablets.
None Documented
None Documented
Norethynodrel: 5-10 hours; mestranol: 2-5 hours (metabolized to ethinyl estradiol, half-life 10-20 hours). Steady-state reached in 5-7 days.
Norelgestromin terminal half-life is approximately 28 hours; ethinyl estradiol terminal half-life is approximately 17 hours. The extended half-life supports once-weekly dosing.
Renal (50-60% as metabolites, <1% unchanged); fecal (40-50%)
Renal excretion of metabolites (primarily ethinyl estradiol and norelgestromin conjugates) accounts for approximately 50% of elimination; fecal/biliary excretion accounts for the remainder (about 35-40% fecal, 10-15% biliary).
Category C
Category C
Oral Contraceptive
Oral Contraceptive