Comparative Pharmacology
Head-to-head clinical analysis: MEGACE ES versus PROVERA.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MEGACE ES versus PROVERA.
MEGACE ES vs PROVERA
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
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.
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.
625 mg orally once daily (MEGACE ES suspension contains 625 mg/5 mL; shake well before use). For appetite stimulation in cachexia.
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
Approximately 34 hours in plasma; steady-state achieved after 2-3 weeks of daily dosing.
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.
Primarily renal (≤1% unchanged) and biliary; extensive metabolism to inactive glucuronide conjugates excreted in feces.
Renal (50-60% as metabolites), biliary/fecal (30-40%). Less than 1% excreted unchanged.
Category C
Category C
Progestin
Progestin