Objective: To evaluate the effectiveness and safety of duloxetine for the treatment of African-American and Hispanic women with stress urinary incontinence.
Research design and methods: The 10-week (a 2-week lead in period followed by 8 weeks of active treatment), open-label, multicenter study of duloxetine 40 mg twice daily included women with stress urinary incontinence or stress predominant mixed incontinence. Efficacy was measured by the median percent change from baseline to endpoint of weekly incontinence episode frequency. The primary objective assessed the treatment response in a pre-specified group of women (n = 2960; 2321 Caucasian, 271 African-American, and 368 Hispanic) with similar baseline incontinence and comorbidity characteristics as the subjects enrolled in the placebo-controlled trials of duloxetine for the treatment of stress urinary incontinence. The efficacy in African-American and Hispanic women was compared with Caucasians using a predefined non-inferiority subpopulation analysis. Safety measures included adverse events, laboratory test results, and vital signs.
Results: All three subgroups reported significant (all p < 0.001) median percent decreases in weekly incontinence episode frequency: -65.7% (African-American), -73.0% (Hispanic), and -75.0% (Caucasian). Non-inferior efficacy was demonstrated for African-American and Hispanic women compared to the Caucasian women. Common adverse events included nausea (21.8%, 28.0%, 25.3%), dry mouth (7.7%, 11.4%, 11.9%), and fatigue (9.2%, 5.7%, 11.6%) for the African-American, Hispanic, and Caucasian groups, respectively.
Conclusion: Duloxetine was efficacious and well tolerated for the treatment of African-American, Hispanic, and Caucasian women with stress urinary incontinence. The trial design was successful in enrolling a diverse population of patients. The most important limitations include the lack of placebo control, the short study duration, and the exclusion of patients with less than seven incontinence episodes per week.