Comparative Pharmacology
Head-to-head clinical analysis: ENOVID E versus NORTREL 1 35 21.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ENOVID E versus NORTREL 1 35 21.
ENOVID-E vs NORTREL 1/35-21
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 of ethinyl estradiol (estrogen) and norethindrone (progestin) suppresses gonadotropin (FSH and LH) release from the pituitary, inhibiting ovulation, altering cervical mucus to impede sperm penetration, and inducing endometrial changes that reduce implantation likelihood.
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: 5-14 hours; Ethinyl estradiol: 17-24 hours. Steady-state achieved after 10 days.
Renal (50-60% as metabolites, <1% unchanged); fecal (40-50%)
Renal 50-60% as metabolites, fecal 40-50% as conjugates, <1% unchanged
Category C
Category C
Oral Contraceptive
Oral Contraceptive