Comparative Pharmacology
Head-to-head clinical analysis: MEGACE ES versus NORETHINDRONE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: MEGACE ES versus NORETHINDRONE.
MEGACE ES vs NORETHINDRONE
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.
Norethindrone is a synthetic progestin that binds to progesterone receptors, suppressing gonadotropin (LH and FSH) release from the pituitary, inhibiting ovulation, and inducing secretory changes in the endometrium. It also has weak androgenic and estrogenic activity.
625 mg orally once daily (MEGACE ES suspension contains 625 mg/5 mL; shake well before use). For appetite stimulation in cachexia.
5 mg orally once daily for 5 days starting on day 5 of menstrual cycle or 0.35 mg orally once daily for contraception.
None Documented
None Documented
Approximately 34 hours in plasma; steady-state achieved after 2-3 weeks of daily dosing.
Terminal elimination half-life: 5-14 hours (mean 8-10 hours); clinical context: requires once-daily dosing for steady state after ~2 days (5 half-lives).
Primarily renal (≤1% unchanged) and biliary; extensive metabolism to inactive glucuronide conjugates excreted in feces.
Renal (30-50% as glucuronide conjugates, 5-10% unchanged), fecal (<10%)
Category C
Category D/X
Progestin
Progestin