Safety and adverse effects associated with raloxifene: Multiple outcomes of raloxifene evaluation

OBJECTIVE: To examine the effect of raloxifene on major adverse events that occur with postmenopausal estrogen therapy or tamoxifen. METHODS: The Multiple Outcomes of Raloxifene Evaluation, a multicenter, randomized, double-blind trial, enrolled 7,705 postmenopausal women with osteoporosis. Women were randomly assigned to raloxifene 60 mg/d or 120 mg/d or placebo. Outcomes included venous thromboembolism, cataracts, gallbladder disease, and endometrial hyperplasia or cancer. RESULTS: During a mean follow-up of 3.3 years, raloxifene,,as associated with an increased risk for venous thromboembolism (relative risk [F-R] 2.1; 95% confidence interval [CI] 1.2-3.8). The excess event rate was 1.8 per 1,000 woman-y ars (95% CI -0.5-4.1), and the number needed to treat to cause 1 event was 170 (95% CI 100-582) over 3.3 years. Risk in the raloxifene group was higher than in the placebo group for the first 2 years, but decreased to about the same rate as in the placebo group thereafter. Raloxifene did riot increase risk for cataracts (RR 0.9; 95% CI 0.8 -1.1), gallbladder disease (RR 1.0; 95% CI 0.7-1.3), endometrial hyperplasia (RR 1.3; 95% CI 0.4-5.1), or endometrial cancer (RR 0.9; 95% CI 0.3-2.7). CONCLUSION: Raloxifene was associated with an increased risk For venous thromboembolism, but there was no increased risk for cataracts, gallbladder disease, endometrial hyperplasia, or endometrial cancer. (C) 2004 by The American College of Obstetricians and Gynecologists.