Comparative Pharmacology
Head-to-head clinical analysis: ENOVID E versus NORLESTRIN 21 2 5 50.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ENOVID E versus NORLESTRIN 21 2 5 50.
ENOVID-E vs NORLESTRIN 21 2.5/50
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 an estrogen (ethinyl estradiol) and a progestin (norethindrone acetate). Inhibits ovulation by suppressing gonadotropin release. Increases viscosity of cervical mucus, impeding sperm penetration, and alters endometrial receptivity.
5 mg orally once daily for 20 days starting on day 5 of menstrual cycle
One tablet orally once daily for 21 days, followed by 7 days off, then repeat.
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.
Norethindrone: 8 hours (terminal); Ethinyl estradiol: 13 hours (terminal). Clinical context: Steady-state achieved after 3-5 days; dosing interval based on once-daily administration.
Renal (50-60% as metabolites, <1% unchanged); fecal (40-50%)
Renal: 50-60% as metabolites (glucuronide and sulfate conjugates of norethindrone and ethinyl estradiol); fecal: 30-40% via biliary elimination; <1% unchanged.
Category C
Category C
Oral Contraceptive
Oral Contraceptive