Comparative Pharmacology
Head-to-head clinical analysis: ENOVID E versus FEMCON FE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ENOVID E versus FEMCON FE.
ENOVID-E vs FEMCON FE
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 oral contraceptive containing norethindrone and ethinyl estradiol. Inhibits ovulation via suppression of gonadotropins (FSH, LH); increases cervical mucus viscosity, impairing sperm penetration; alters endometrial receptivity.
5 mg orally once daily for 20 days starting on day 5 of menstrual cycle
One tablet (norethindrone 0.5 mg + ethinyl estradiol 35 mcg) orally once daily for 28 days.
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.
The terminal elimination half-life of ethinyl estradiol is 13-18 hours; for norethindrone, it is 7-12 hours. Both allow once-daily dosing for contraceptive efficacy.
Renal (50-60% as metabolites, <1% unchanged); fecal (40-50%)
Renal excretion accounts for approximately 40-60% of the dose as metabolites; fecal excretion is about 20-30% via bile. Unchanged drug excretion is minimal.
Category C
Category C
Oral Contraceptive
Oral Contraceptive