Comparative Pharmacology
Head-to-head clinical analysis: ETHINYL ESTRADIOL ETONOGESTREL versus PROVERA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ETHINYL ESTRADIOL ETONOGESTREL versus PROVERA.
ETHINYL ESTRADIOL; ETONOGESTREL vs PROVERA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
ETHINYL ESTRADIOL is an estrogen; ETONOGESTREL is a progestin. The combination suppresses gonadotropin (FSH and LH) release from the pituitary, inhibiting ovulation, thickening cervical mucus to impede sperm penetration, and altering endometrial receptivity.
Provera (medroxyprogesterone acetate) is a progestin that binds to progesterone receptors, suppressing gonadotropin secretion, inhibiting endometrial growth, and inducing secretory changes in the endometrium. It also has antigonadotropic effects by reducing LH and FSH release from the pituitary.
One vaginal ring (0.120 mg etonogestrel/0.015 mg ethinyl estradiol per day) inserted vaginally and left in place for 3 weeks, followed by a 1-week ring-free period.
Oral: 5-10 mg daily for 5-10 days for secondary amenorrhea; 5-10 mg daily for 12-14 days per cycle in combination with estrogen for endometrial hyperplasia; 400-1000 mg/day IM monthly for endometriosis.
None Documented
None Documented
Ethinyl estradiol: ~13 hours (range 7-20 h); etonogestrel: ~25 hours (range 15-36 h). At steady state, elimination half-life extends to 20-30 h for etonogestrel.
Terminal elimination half-life is approximately 12-17 hours for medroxyprogesterone acetate (oral). With depot intramuscular injection, the half-life is extended to approximately 50 days due to slow absorption from the injection site.
Urine (60-70% as metabolites, <10% unchanged), feces (20-30% via biliary elimination).
Renal (50-60% as metabolites), biliary/fecal (30-40%). Less than 1% excreted unchanged.
Category D/X
Category C
Progestin
Progestin