Medroxyprogesterone interferes with ovarian steroid protection against coronary vasospasm.

Authors: Miyagawa K, Rosch J, Stanczyk F, Hermsmeyer K.

Publication Year:1997

Citation: Nat Med 1997; 3(3): 324-7.

Ovariectomized rhesus monkeys were treated with physiological levels of 17-beta estradiol in combination with either medroxyprogesterone or progesterone (oral micronized) for four weeks. Following pathophysiological stimulation without injury to induce coronary vasospasm, it was shown that progesterone plus estradiol was protective against vasospasm, whereas estradiol plus medroxyprogesterone allowed vasospasm, concluding that medroxyprogesterone increases risk of coronary vasospasm, while progesterone does not.

http://www.ncbi.nlm.nih.gov/pubmed/9055861