Provera Mechanism of Action

Pharmacology: Medroxyprogesterone acetate, administered orally or parenterally in the recommended doses to women with adequate endogenous estrogen, transforms proliferative into secretory endometrium. The drug is progestational agent devoid of estrogenic activity. Minimal androgenic and anabolic effects may occur. While parenterally administered medroxyprogesterone acetate inhibits gonadotropin production, which in turn prevents follicular maturation and ovulation, available data indicate that this does not occur when the usually recommended oral dosage is given as single daily doses.
Administration with food increases the bioavailability of MPA. A 10 mg dose of oral MPA, taken immediately before or after a meal, increased average MPA C_max (51% and 77%, respectively) and average AUC (18 and 33%, respectively). The half-life of MPA was not changed with food.
100 mg: The anti-cancer activity of PROVERA at pharmacologic doses in the case of specific forms of hormone-dependent cancers may be due to its effect on the hypothalamic-pituitary-gonadal axis, estrogen receptors and the metabolism of steroids at the tissue level.