Comparative Pharmacology
Head-to-head clinical analysis: ETHINYL ESTRADIOL ETONOGESTREL versus MEGACE ES.
Peer-Reviewed Evidence
Head-to-head clinical analysis: ETHINYL ESTRADIOL ETONOGESTREL versus MEGACE ES.
ETHINYL ESTRADIOL; ETONOGESTREL vs MEGACE ES
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.
Megestrol acetate is a synthetic progestin that inhibits pituitary gonadotropin secretion, leading to suppression of ovarian and testicular hormone production. It also has antineoplastic effects possibly through local action on hormone-sensitive tissues and stimulates appetite via modulation of neuropeptide Y and other appetite-regulating factors.
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.
625 mg orally once daily (MEGACE ES suspension contains 625 mg/5 mL; shake well before use). For appetite stimulation in cachexia.
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.
Approximately 34 hours in plasma; steady-state achieved after 2-3 weeks of daily dosing.
Urine (60-70% as metabolites, <10% unchanged), feces (20-30% via biliary elimination).
Primarily renal (≤1% unchanged) and biliary; extensive metabolism to inactive glucuronide conjugates excreted in feces.
Category D/X
Category C
Progestin
Progestin