Comparative Pharmacology
Head-to-head clinical analysis: ENOVID versus LEVORA 0 15 30 28.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ENOVID versus LEVORA 0 15 30 28.
ENOVID vs LEVORA 0.15/30-28
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Combination estrogen-progestin contraceptive; suppresses gonadotropins (LH, FSH) via negative feedback on hypothalamic-pituitary axis, inhibiting ovulation; increases viscosity of cervical mucus and alters endometrial lining to impair implantation.
Combination oral contraceptive containing ethinyl estradiol and levonorgestrel. Suppresses gonadotropin (FSH and LH) release from the pituitary, inhibiting ovulation. Also induces changes in cervical mucus (increasing viscosity) and endometrium (reducing receptivity) to impair sperm penetration and implantation.
Oral, 5 mg daily for 20 days starting on day 5 of menstrual cycle for ovulation inhibition; for endometriosis, 5 mg daily for 15 days increasing to 10 mg daily if breakthrough bleeding occurs.
One tablet orally once daily at the same time each day for 28 days (21 active tablets containing 0.15 mg levonorgestrel and 0.03 mg ethinyl estradiol, followed by 7 placebo tablets).
None Documented
None Documented
Norethynodrel: 5-12 hours; mestranol: 7-20 hours. Terminal half-life of ethinyl estradiol from mestranol conversion: 10-30 hours. Clinical context: steady-state achieved after 3-5 half-lives (3-5 days).
Ethinyl estradiol: 13-27 hours (terminal); Levonorgestrel: 11-45 hours (terminal, dose-dependent due to SHBG binding).
Renal (30-50% as metabolites, <5% unchanged) and fecal (40-60% via bile, mostly as glucuronide conjugates).
Renal: ~50% (as glucuronide and sulfate conjugates of ethinyl estradiol and levonorgestrel); Fecal: ~50% (enterohepatic recirculation).
Category C
Category C
Oral Contraceptive
Oral Contraceptive