Comparative Pharmacology
Head-to-head clinical analysis: HYDROXYPROGESTERONE CAPROATE versus MEGACE.
Peer-Reviewed Evidence
Head-to-head clinical analysis: HYDROXYPROGESTERONE CAPROATE versus MEGACE.
HYDROXYPROGESTERONE CAPROATE vs MEGACE
Comparing the clinical profiles, pharmacokinetic behaviors, and safety indices of these two therapeutic agents.
Hydroxyprogesterone caproate is a synthetic progestin that acts as an agonist of the progesterone receptor. Its mechanism in preventing preterm birth is not fully understood but may involve suppression of uterine contractility, maintenance of cervical integrity, and modulation of the inflammatory response.
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.
250-500 mg intramuscularly once weekly. For recurrent preterm birth prevention: 250 mg intramuscularly weekly starting at 16-20 weeks gestation until 36 weeks.
Oral: 625 mg (suspension) or 400–800 mg (tablets) once daily.
None Documented
None Documented
Clinical Note
moderateHydroxyprogesterone caproate + Digoxin
"Hydroxyprogesterone caproate may decrease the cardiotoxic activities of Digoxin."
Clinical Note
moderateHydroxyprogesterone caproate + Digitoxin
"Hydroxyprogesterone caproate may decrease the cardiotoxic activities of Digitoxin."
Clinical Note
moderateHydroxyprogesterone caproate + Deslanoside
"Hydroxyprogesterone caproate may decrease the cardiotoxic activities of Deslanoside."
Clinical Note
moderateHydroxyprogesterone caproate + Acetyldigitoxin
Terminal elimination half-life is approximately 7-8 days (range 5-14 days) due to slow release from the intramuscular depot, supporting weekly or biweekly dosing.
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.
Primarily renal as metabolites; approximately 50-60% of a dose is excreted in urine within 96 hours, with less than 5% as unchanged drug. Biliary/fecal excretion accounts for approximately 30-40%.
Primarily renal: ~75% as glucuronide conjugates and unchanged drug; biliary/fecal: ~25% as metabolites.
Category D/X
Category C
Progestin
Progestin
"Hydroxyprogesterone caproate may decrease the cardiotoxic activities of Acetyldigitoxin."