Comparative Pharmacology
Head-to-head clinical analysis: MEGESTROL ACETATE versus PROGESTERONE VAGINAL.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MEGESTROL ACETATE versus PROGESTERONE VAGINAL.
MEGESTROL ACETATE vs Progesterone (Vaginal)
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Synthetic progestin with antineoplastic activity; suppresses pituitary gonadotropin secretion and exerts direct cytotoxic effects on endometrial cancer cells via binding to progesterone receptors. Also stimulates appetite through unclear mechanisms, possibly involving neuropeptide Y and inhibition of proinflammatory cytokines.
Progesterone binds to progesterone receptors in the reproductive tract, converting proliferative endometrium to secretory endometrium, and reduces gonadotropin secretion, inhibiting ovulation.
400 mg orally once daily or 800 mg orally once daily (suspension) for appetite stimulation; 40-320 mg orally daily in divided doses for endometrial cancer.
For progesterone deficiency (e.g., assisted reproductive technology, luteal phase support): 90 mg intravaginally once daily. For secondary amenorrhea: 45 mg intravaginally every other day for up to 12 doses, then 90 mg if needed. For threatened abortion: 200-400 mg intravaginally once or twice daily.
None Documented
None Documented
Clinical Note
moderateMegestrol acetate + Digoxin
"Megestrol acetate may decrease the cardiotoxic activities of Digoxin."
Clinical Note
moderateMegestrol acetate + Digitoxin
"Megestrol acetate may decrease the cardiotoxic activities of Digitoxin."
Clinical Note
moderateMegestrol acetate + Deslanoside
"Megestrol acetate may decrease the cardiotoxic activities of Deslanoside."
Clinical Note
moderateMegestrol acetate + Acetyldigitoxin
Terminal half-life: 13-105 hours (mean ~34 hours) in adults; prolonged in hepatic impairment.
The terminal elimination half-life of progesterone administered vaginally is approximately 5.5 to 6 hours (range: 4.5–8.0 hours) in women with normal renal and hepatic function. This short half-life necessitates twice-daily dosing for sustained effects.
Renal: 50-79% as glucuronide conjugates; fecal: 8-30%; biliary: minor.
Primarily hepatic metabolism; about 50-60% of metabolites are excreted renally as glucuronide conjugates, with approximately 30-40% eliminated via feces. Less than 1% of unchanged progesterone is excreted in urine.
Category D/X
Category A/B
Progestin
Progestin
"Megestrol acetate may decrease the cardiotoxic activities of Acetyldigitoxin."