Raloxifene, a new selective estrogen receptor modulator.

There is evidence from observational studies that estrogen replacement therapy in postmenopausal women can reduce the rates of morbidity and mortality of atherosclerotic heart disease. The mechanism of this cardiovascular protective effect is not yet established, but favorable actions of hormone therapy on plasma lipids and vascular endothelial function have been proposed. Estrogens can also increase the risk of breast and uterine carcinoma. The new selective estrogen receptor modulator (SERM) raloxifene appears to have benefits similar to estrogen on plasma lipids and osteoporosis, but it does not affect the rate of uterine carcinoma as does tamoxifen and estrogen. Animal studies suggest an anti-atherosclerotic action of raloxifene, but this needs to be confirmed in long-term human studies.