Comparative Pharmacology
Head-to-head clinical analysis: AYGESTIN versus MEGACE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: AYGESTIN versus MEGACE.
AYGESTIN vs MEGACE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Progestin that suppresses gonadotropin secretion, inhibits ovulation, and induces endometrial changes by binding to progesterone receptors.
Megestrol acetate is a synthetic progestin that inhibits pituitary gonadotropin secretion, leading to suppression of ovarian function and reduction of sex hormone levels. It also has antineoplastic effects through interference with estrogen receptor binding and may stimulate appetite via effects on neuropeptide Y and cytokines.
5 mg orally once daily for secondary amenorrhea; 5 mg orally once daily from day 5 to day 25 of menstrual cycle for abnormal uterine bleeding.
Oral: 625 mg (suspension) or 400–800 mg (tablets) once daily.
None Documented
None Documented
Terminal half-life 5-12 hours; clinical context: requires twice-daily dosing for consistent serum levels.
Terminal elimination half-life: 70-95 hours (mean 85 hours) in chronic dosing; shorter in initial doses; clinical context: requires 3-4 weeks to reach steady state.
Approximately 50-80% renal as metabolites, 10-20% fecal; less than 1% unchanged.
Primarily renal: ~75% as glucuronide conjugates and unchanged drug; biliary/fecal: ~25% as metabolites.
Category C
Category C
Progestin
Progestin