THE EFFECT OF MEDROXYPROGESTERONE ACETATE AND CLOMIPHENE CITRATE ON PLATELET-FUNCTION IN MENOPAUSAL WOMEN

Objective: We sought to determine if antiestrogens such as clomiphene citrate (CC) and medroxyprogesterone acetate (MPA) affect platelet act ivity in postmenopausal patients before and after treatment with estro gens. Methods: Using an incubation study, we analyzed the effects of C C and MPA on adenosine diphosphate and adrenaline-induced platelet agg regation and on the release of adenosine triphosphate in postmenopausa l patients, using a platelet study, we analyzed the effect of these dr ugs on platelet function. Results: Platelets were inhibited by MPA and CC in the incubation study but not significantly affected in the plat elet study. Platelets previously incubated with estrogen were less inh ibited by CC than by MPA. Discussion: Thus, platelet study to determin e the optimal combination therapy for menopausal patients has indicate d that CC has a non-significantly less beneficial in vitro effect on p latelet function than MPA.