Objective: The efficacy and safety of low-dose paroxetine 7.5 mg for the treatment of menopausal vasomotor symptoms were evaluated in two multicenter, double-blind, placebo-controlled, phase 3 studies of 12 and 24 weeks' duration.
Methods: Postmenopausal women were randomly assigned 1:1 to receive paroxetine 7.5 mg or placebo once daily. The four primary efficacy endpoints included mean changes in the frequency and severity of moderate to severe vasomotor symptoms on weeks 4 and 12; an additional endpoint was persistence of treatment benefit on week 24.
Results: Five hundred ninety-one participants were randomly assigned to treatment with paroxetine 7.5 mg, and 593 participants were randomly assigned to treatment with placebo. All primary endpoints were met in the 24-week study; three of four primary endpoints were met in the 12-week study. In both studies, paroxetine 7.5 mg significantly reduced the mean weekly vasomotor symptom frequency compared with placebo on week 4 (P < 0.0001 for both studies) and week 12 (P = 0.0090, 12-wk study; P = 0.0001, 24-wk study). Mean weekly reduction in vasomotor symptom severity was significantly greater for paroxetine 7.5 mg than for placebo on week 4 (P = 0.0048) in the 12-week study and on week 4 (P = 0.0452) and week 12 (P = 0.0114) in the 24-week study. Persistence of treatment benefit was demonstrated in the 24-week study. Most treatment-emergent adverse events were mild or moderate in severity. No clinically significant changes in laboratory values or vital signs were noted, and no short-term discontinuation of symptoms followed treatment cessation.
Conclusions: Paroxetine 7.5 mg is well-tolerated, is effective in reducing the frequency and severity of menopausal vasomotor symptoms, and demonstrates persistence of treatment benefit through 24 weeks of treatment.
Trial registration: ClinicalTrials.gov NCT01101841 NCT01361308.