In a study recently reported in The New England Journal of Medicine, approximately 600 postmenopausal women from eight European countries were randomly assigned to treatment with one of three doses of raloxifene placebo for two years. Those receiving raloxifene experienced increases in bone density of their lower spine, hip and total body along with a drop in blood levels of LDL cholesterol. Raloxifene is the second of a new class of synthetic estrogenic compounds that have selective actions on different tissues. The first to reach the market, tamoxifen, blocks the ability of natural estrogens to stimulate growth of breast tissue. It is now widely used in women who have had breast cancer to prevent cancer in the second breast.
Tamoxifen also decreases the risk of heart attack by lowering cholesterol levels in the blood.
However, it can cause cancer of the endometrium. Both tamoxifen and raloxifene take advantage of the discovery that estrogen receptors behave differently in different tissues, depending on the nature of the estrogenic compound that hooks up with them. It is not yet known whether raloxifene, like natural estrogens, will decrease the tendency of the blood to form circulation-blocking clots. And still unexplored is whether raloxifene can prevent or slow the progression of Alzheimer's disease. The FDA announced new steps to provide health care professionals with the information necessary to prescribe medications more safely for children.