Short- and long-term efficacy and safety of duloxetine in women with predominant stress urinary incontinence

Abstract

Objective: To evaluate short- and long-term safety and efficacy of duloxetine in women with predominant stress urinary incontinence (SUI).

Research design and methods: The study was a 6-week, double-blind, randomised, parallel, placebo-controlled study followed by an uncontrolled open-label extension (OLE) run in 342 study centres in 16 European countries. Women with predominant SUI were randomly assigned to placebo (n = 1380) or duloxetine 40 mg twice daily (n = 1378) for 6 weeks. Completers of the acute phase were enrolled in the OLE, which had a minimum duration of 6 weeks and ended, based on the approval status of duloxetine in the participating country.

Main outcome measures: The primary outcome measure was the change in incontinence episode frequency (IEF) over 6 weeks. Secondary outcome measures were the long-term maintenance of effect on IEF and Patient Global Impression of Improvement (PGI-I), the short- and long-term impact on quality of life using the King's Health Questionnaire (KHQ), and the long-term safety of duloxetine.

Results: After 6 weeks, the decrease in weekly IEF was significantly greater with duloxetine treatment compared to placebo (-50.0 vs. -29.9%; p < 0.001). The percentage of responders (defined as > or =50% decrease in IEF) was significantly higher with duloxetine treatment than with placebo (50.6 vs. 31.2%; p < 0.001). Duloxetine treatment was associated with improvements in weekly pad use (-31.4%), PGI-I ratings (63.6%), and KHQ score (-6.25) compared to placebo (-12.5%, 48.5% and -3.13, respectively, all p < 0.001). Treatment-emergent adverse events were significantly more common during duloxetine treatment (48.3%) than placebo (33.3%), (p < 0.001). Of the 2290 patients continuing into the OLE, 1165 (42.2%) completed the available duration, and 592 (21.5%) discontinued because of an adverse event (percentages relative to total randomised patients). Long-term efficacy in the OLE was assessed over a 72-week period and was maintained over that time. However, the results should be interpreted within the context that better responding patients are more likely to remain on duloxetine, while patients responding poorly are more likely to discontinue over time.

Conclusions: Duloxetine seems to be an efficacious treatment with an acceptable safety profile for women with SUI. Achieved improvement is maintained over the longer term in those women who remain on therapy.

Trial registration: ClinicalTrials.gov NCT00190996.