Influence of raloxifene on the efficacy of an estradiol-releasing ring for treating vaginal atrophy in postmenopausal women

Objective: To determine the potential interaction of oral raloxifene 60 mg/day on the efficacy of a low-dose, estradiol-releasing vaginal ring used to treat signs and symptoms of vaginal atrophy in postmenopausal women. Design: Randomized, double-blind, placebo-controlled, parallel treatment trial of raloxifene and placebo with open-label 17beta-estradiol ring. At 10 sites in the United States, 91 postmenopausal women with at least two signs of vaginal atrophy were treated with a 17beta-estradiol ring and randomized to receive concomitant raloxifene 60 mg/day or placebo for 6 months. Efficacy of treatments was evaluated by comparing investigator assessments of genitourinary atrophic signs, vaginal maturation value, and participant assessments of vaginal symptoms at 6 months. Other measures included rate and severity of hot flashes and assessment of sexual function. Uterine safety was assessed by endometrial biopsy and transvaginal ultrasound. Results: In women treated with a 17beta-estradiol ring, both the raloxifene and placebo treatment groups showed improvements in signs and symptoms of vaginal atrophy at 6 months, with no significant differences in degree of improvement between groups. There were no signs of endometrial proliferation in either group. Conclusions: Concomitant administration of raloxifene does not alter the effects of the 17beta-estradiol ring on alleviating signs and symptoms of genitourinary atrophy in postmenopausal women.