Desvenlafaxine compared with placebo for treatment of menopausal vasomotor symptoms: a 12-week, multicenter, parallel-group, randomized, double-blind, placebo-controlled efficacy trial.

OBJECTIVE The aim of this study was to assess the 12-week efficacy of desvenlafaxine in treating moderate to severe vasomotor symptoms and the clinical relevance of improvements in postmenopausal women experiencing 50 or more moderate to severe hot flashes per week. METHODS Participants were randomized to placebo or desvenlafaxine 100 mg/day in the 12-week efficacy substudy of a year-long, multicenter, parallel-group, double-blind study. Coprimary outcomes were changes from baseline in the daily number and severity of hot flashes on weeks 4 and 12. The percentage of women achieving the minimal clinically important difference (MCID) in the number of hot flashes on week 12 was determined. RESULTS The efficacy substudy modified intent-to-treat population included 365 women (desvenlafaxine, n = 184; placebo, n = 181). Desvenlafaxine 100 mg/day significantly reduced the number and severity of hot flashes versus placebo on week 4 (P < 0.001) and week 12 (P < 0.001). On week 12, desvenlafaxine reduced the number of moderate and severe hot flashes by 7.3 (62%) per day (placebo, -4.5 [38%] per day) and the severity score by 0.59 (25%) per day (placebo, -0.28 [12%] per day). MCID-a reduction of 5.35 moderate and severe hot flashes per day-was achieved by 64% of desvenlafaxine-treated women (placebo, 41%; P < 0.001). In all, 17.2% (67/390) of participants discontinued, 10.0% (20/200) of participants taking desvenlafaxine and 3.7% (7/190) of participants taking placebo discontinued because of adverse events (P = 0.016), and 2.5% (5/200) of participants taking desvenlafaxine and 8.4% (16/190) of participants taking placebo discontinued because of lack of efficacy (P = 0.012). CONCLUSIONS Postmenopausal women with moderate to severe hot flashes who are treated with desvenlafaxine achieve rapid symptom reduction that is clinically relevant based on MCID.