Raloxifene

Raloxifene is a selective estrogen receptor modulator which mimics the effects of estrogens on bone and blood lipid levels without stimulatory effects on the breast or uterus. Raloxifene inhibits estrogen-dependent proliferation of human breast cancer cells in vitro and development of induced mammary tumours in rats in vivo. Raloxifene inhibits bone resorption induced by estrogen deficiency in murine and human studies and lowers serum cholesterol levels. In clinical studies in postmenopausal women, raloxifene 60 mg/day for 2 years significantly increased bone mineral density compared with placebo. In comparative clinical studies, raloxifene 60 mg/day had more modest effects than conjugated estrogens 0.625 mg/day on bone resorption and formation parameters and appeared to be less effective in increasing bone mineral density. In older postmenopausal women with existing bone fractures, raloxifene 60 or 120 mg/day for 1 year produced modest increases in bone mineral density. The most common treatment-related adverse events in raloxifene recipients were hot flushes and leg cramps. The risk of venous thromboembolic events is increased during raloxifene therapy. In contrast with conjugated estrogens 0.625 mg/day, raloxifene 200 or 600 mg/day for 8 weeks or 150 mg/day for 1 year did not produce endometrial proliferation.