Objective: Duloxetine, a serotonin/norepinephrine reuptake inhibitor, has been effective in the treatment of mild and moderate stress urinary incontinence. The aim of this trial was to assess its efficacy for women with severe stress urinary incontinence.
Methods: One hundred nine women, aged 33-75 years, enrolled into this double-blind, randomized, placebo-controlled study. Subjects had to have a predominant symptom of stress urinary incontinence with an incontinence episode frequency 14 per week or more, pure urodynamic stress urinary incontinence, and continence surgery already scheduled. Women were randomized to placebo (n = 54) or duloxetine 80 mg/d (n = 55) for 4 weeks, escalated to 120 mg/d for 4 weeks. Assessment variables included incontinence episode frequency, continence pad use, the Incontinence Quality of Life (I-QOL) questionnaire, and the Willingness to Consider Surgery rating. A responder was defined as a subject with an incontinence episode frequency reduction of 50% or more.
Results: There were significant improvements with duloxetine compared with placebo in incontinence episode frequency (-60% versus -27%, P <.001), I-QOL score (+10.6 versus +2.4, P =.003), and pad use (-34.5% versus -4.8%, P =.008). At the conclusion of the 8-week study, 10/49 (20%) duloxetine-treated women were no longer interested in surgery, compared with 0/45 placebo-treated women (P =.001). Duloxetine-treated subjects were significantly more likely to be classified as responders (relative risk 4.68, 95% confidence interval 2.27-9.66). The number of subjects-needed-to-treat to gain an additional incontinence episode frequency responder with duloxetine was 2.02. All duloxetine responses were observed within 2 weeks. Side effects and discontinuations because of side effects were significantly more common with duloxetine.
Conclusion: The data support duloxetine's efficacy in women with severe stress urinary incontinence and suggest that some women responding to duloxetine may reconsider their willingness to undergo surgery.