The effects of progestins on vasomotor flushes

For patients with severe vasomotor flushes who require therapy but for whom estrogens are contraindicated, progestins can be tried. These drugs appear to offer the benefit of a reduction of vasomotor flushes without such unwanted side effects as the increased risk of contracting endometrial cancer. However, progestins cannot replace estrogens universally since there is no evidence that they prove effective against osteoporosis-related fractures and genital atrophy. Nonetheless, as more physicians begin to add medroxyprogesterone acetate to the estrogen regimen to reduce the risk of endometrial hyperplasia, it might be that a lower dose of estrogen will be necessary to relieve flushes. We hope that this additive effect exists, although it has not yet been shown. Whether or not the addition of medroxyprogesterone will carry risks or counteract the beneficial effects of estrogens on such disorders as osteoporosis remains to be elucidated. What is clear from the medroxyprogesterone and estrogen studies is that whenever these drugs are discontinued, the vasomotor flushes can recur, albeit with less intensity and less frequency.