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 activity in postmenopausal patients before and after treatment with estrogens.


METHODS
Using an incubation study, we analyzed the effects of CC and MPA on adenosine diphosphate and adrenaline-induced platelet aggregation and on the release of adenosine triphosphate in postmenopausal patients, using a platelet study, we analyzed the effect of these drugs on platelet function.


RESULTS
Platelets were inhibited by MPA and CC in the incubation study but not significantly affected in the platelet study. Platelets previously incubated with estrogen were less inhibited by CC than by MPA.


CONCLUSIONS
Thus, platelet study to determine the optimal combination therapy for menopausal patients has indicated that CC has a non-significantly less beneficial in vitro effect on platelet function than MPA.
Tepper
R
R
Department of Obstetrics and Gynecology, Sapir Medical Center, Kfar Saba, Israel.
Bar
J
J
Goldberger
S
S
Fuchs
J
J
Beyth
Y
Y
Ovadia
J
J
D000244:Adenosine Diphosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000378:metabolism; D000328:Adult; D001792:Blood Platelets / Q000187:drug effects*; D002478:Cells, Cultured; D002996:Clomiphene / Q000494:pharmacology* / Q000627:therapeutic use; D004837:Epinephrine / Q000494:pharmacology; D004965:Estrogen Antagonists / Q000494:pharmacology* / Q000627:therapeutic use; D015914:Estrogen Replacement Therapy; D005260:Female; D006801:Humans; D017258:Medroxyprogesterone Acetate / Q000494:pharmacology* / Q000627:therapeutic use; D008593:Menopause; D008875:Middle Aged; D015539:Platelet Activation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000494:pharmacology; D017698:Postmenopause; D045167:Progesterone Congeners / Q000494:pharmacology* / Q000627:therapeutic use
D004965:Estrogen Antagonists; D010975:Platelet Aggregation Inhibitors; D045167:Progesterone Congeners; D002996:Clomiphene; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D017258:Medroxyprogesterone Acetate; D004837:Epinephrine