Efficacy and Safety of Once-daily Oxybutynin Patch Versus Placebo and Propiverine in Japanese Patients with Overactive Bladder: A Randomized Double-blind Trial

Objectives: To evaluate the efficacy and safety of once-daily oxybutynin patch therapy for overactive bladder.

Methods: A randomized double-blind trial was carried out in patients with overactive bladder syndrome, who received an oxybutynin patch, propiverine (20 mg) or placebo once daily for 12 weeks. The primary efficacy end-point was the change of the mean daily number of micturitions in week 12.

Results: A total of 1530 patients were randomized to receive the oxybutynin patch (573), propiverine (576) or placebo (381). The change of the mean daily frequency of micturition from baseline in the full analysis set was -1.89 ± 2.04 with the oxybutynin patch, which was significantly higher than with placebo (-1.44 ± 2.23) (P = 0.0015). The difference of the mean change in the mean daily number of micturitions between the oxybutynin patch and propiverine groups showed a 95% confidence interval of -0.28 to 0.21, and the upper limit of this interval was below the predefined non-inferiority margin of 0.37, showing non-inferiority of the oxybutynin patch to propiverine. The incidence of dry mouth and constipation was higher with propiverine than with the oxybutynin patch or placebo. Application site dermatitis was more frequent with the oxybutynin patch (31.8%) than with propiverine (5.9%) or placebo (5.2%), but the dermatitis was generally mild.

Conclusion: This trial shows the efficacy of the new once-daily oxybutynin patch for overactive bladder. Despite a higher rate of dermatitis with the oxybutynin patch, dry mouth and constipation occurs less often than during treatment with propiverine.