Stress urinary incontinence is involuntary urine leakage on coughing or exertion. The trials reviewed compared duloxetine against dummy placebo tablets and also pelvic floor muscle training in women with predominantly stress urinary incontinence. Duloxetine reduced the frequency of episodes of incontinence and improved quality of life scores. However, it had little impact on the numbers cured and commonly had side effects, especially nausea. More studies comparing a serotonin and noradrenaline reuptake inhibitor with placebo and surgery are required, especially if conducted independently of pharmaceutical companies.
The available evidence suggests that duloxetine treatment can significantly improve the quality of life of patients with stress urinary incontinence, but it is unclear whether or not benefits are sustainable. Adverse effects are common but not serious. About one in three participants allocated duloxetine reported adverse effects (most commonly nausea) related to treatment, and about one in eight allocated duloxetine stopped treatment as a consequence.
To date, standard recommendations for the management of stress urinary incontinence (SUI) would be either pelvic floor muscle training (PFMT) or surgery. A new form of drug treatment with a serotonin-noradrenaline reuptake inhibitor (SNRI), duloxetine, may now have a place in treatment of this condition.
To determine whether a SNRI is better than placebo (or no treatment, other pharmacological and non-pharmacological therapies, or surgery) in the treatment of women with SUI, or mixed urinary incontinence that includes stress incontinence (MUI), or both and which doses should be used.
We searched the Cochrane Incontinence Group Specialised Register (searched 5th March 2007), CENTRAL (The Cochrane Library 2006, Issue 4), MEDLINE (January 1966 to January 2007), MEDLINE In-Process & Other Non-Indexed Citations (7 February 2007) and the reference lists of relevant articles.
All randomised or quasi-randomised controlled trials of treatment for SUI or MUI, in which at least one management arm involved a SNRI.
Two authors evaluated the trials for appropriateness for inclusion and methodological quality. Three authors performed the data extraction using predetermined criteria. Analyses were performed using the Cochrane Review Manager software, RevMan.
Ten randomised trials were included, involving 3944 adults with predominantly SUI, randomised to receive duloxetine or placebo and/ or PFMT. All arms in individual trials were comparable for various baseline characteristics. Treatment duration was between three weeks and 12 weeks.
Duloxetine was significantly better than placebo in terms of improving patients' quality of life (weighted mean difference 5.26, 95% confidence interval 3.84 to 6.68. P less than 0.00001) and perception of improvement. Individual studies demonstrated a significant reduction in the Incontinence Episode Frequency (IEF) by approximately 50% during treatment with duloxetine. With regard to objective cure, however, meta-analysis of stress pad test and 24 hour pad weight change failed to demonstrate a benefit for duloxetine over placebo though data were relatively few. Subjective cure favoured duloxetine, albeit with a small effect size (3%). One trial suggested that duloxetine was better than pelvic floor muscle training alone in reducing IEF (P less than 0.05) based on median percentage decrease in IEF per week. Although significant side effects were commonly associated with duloxetine, they were reported as acceptable.