Comparative Pharmacology
Head-to-head clinical analysis: MEGACE ES versus PROGESTERONE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MEGACE ES versus PROGESTERONE.
MEGACE ES vs PROGESTERONE
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.
Progesterone binds to progesterone receptors (PR-A and PR-B) in target tissues, modulating gene expression to induce secretory changes in the endometrium, support pregnancy, and regulate gonadotropin secretion via negative feedback on the hypothalamic-pituitary axis.
625 mg orally once daily (MEGACE ES suspension contains 625 mg/5 mL; shake well before use). For appetite stimulation in cachexia.
Oral: 200-400 mg daily in 1-2 divided doses; Intramuscular: 50-100 mg daily; Vaginal: 200-400 mg daily in 1-2 divided doses.
None Documented
None Documented
Clinical Note
moderateMedroxyprogesterone acetate + Digoxin
"Medroxyprogesterone acetate may decrease the cardiotoxic activities of Digoxin."
Clinical Note
moderateHydroxyprogesterone caproate + Digoxin
"Hydroxyprogesterone caproate may decrease the cardiotoxic activities of Digoxin."
Clinical Note
moderateMedroxyprogesterone acetate + Digitoxin
"Medroxyprogesterone acetate may decrease the cardiotoxic activities of Digitoxin."
Clinical Note
moderateHydroxyprogesterone caproate + Digitoxin
Approximately 34 hours in plasma; steady-state achieved after 2-3 weeks of daily dosing.
Elimination half-life: approximately 5-15 minutes for intravenous progesterone; terminal half-life of metabolites (pregnanediol) is about 2-8 hours, but clinical effects (e.g., endometrial transformation) persist for days due to receptor-mediated activity.
Primarily renal (≤1% unchanged) and biliary; extensive metabolism to inactive glucuronide conjugates excreted in feces.
Renal (50-60% as metabolites) and fecal (10-20%). Biliary excretion of metabolites occurs; enterohepatic recirculation may contribute to prolonged presence. Unchanged drug negligible in urine.
Category C
Category D/X
Progestin
Progestin
"Hydroxyprogesterone caproate may decrease the cardiotoxic activities of Digitoxin."