Duloxetine: new drug. For stress urinary incontinence: too much risk, too little benefit.

(1) The first-line treatment for women with stress urinary incontinence consists of pelvic floor exercises, which are risk-free and effective in two-thirds to three-quarters of cases. (2) Duloxetine, a serotonin and norepinephrine reuptake inhibitor, is the first drug to be marketed in France for the treatment of moderate to severe stress urinary incontinence, after receiving European marketing authorization. (3) A dose-ranging study and three placebo-controlled trials lasting no more than three months showed that duloxetine reduced the frequency of stress incontinence by a median of one episode a day as compared with placebo. The tangible impact of duloxetine on quality of life is doubtful, with a maximum gain of five points on a 100-point scale. (4) A trial lasting 36 weeks showed that duloxetine was no more effective than placebo. (5) One trial compared a combination of physiotherapy and duloxetine versus each treatment alone and placebo. The published report of this trial is restricted to the duloxetine-placebo comparison, which raises doubts as to the possible benefit of the combination of duloxetine and physiotherapy. (6) About one-quarter of patients enrolled in clinical trials stopped taking duloxetine after less than three months because of adverse effects. More than 40 different types of adverse effects have been reported, including suicide attempts and potentially severe hepatic disorders. (7) Duloxetine is metabolised by the cytochrome P450 isoenzymes CYP 1A2 and CYP 2D6, creating a risk of interactions with other drugs that follow these metabolic pathways. (8) In practice, purely symptomatic treatments that have no documented efficacy but many adverse effects should not be used, especially when there is an alternative treatment with a positive risk-benefit balance.