A comparison of extended-release oxybutynin and tolterodine for treatment of overactive bladder in women

Women with urge or mixed incontinence were randomized to a daily dose of 10 mg extended-release oxybutynin chloride (qd) or tolterodine tartrate 4 mg (2 mg bid) for 12 weeks. Subjects completed 7-day voiding diaries at baseline and at 12 weeks. A total of 315 women were treated. At the end of the study, extended-release oxybutynin chloride was more effective than twice-daily tolterodine tartrate as measured by urge and total incontinence episodes (p=0.038, p=0.030, respectively). Overall, the reduction in micturition frequency between groups was not significantly different. In women aged 64 years and younger (comprising 63% of the population) extended-release oxybutynin was more effective than tolterodine for urge (p=0.005) and total incontinence (p=0.005), and for micturition frequency (0.024). Adverse events were infrequent, mostly mild, and similar between treatment groups. We concluded that daily extended-release oxybutynin chloride (10 mg) was more effective than tolterodine tartrate (2 mg bid) in treating urge and total incontinence. The incidences of dry mouth, CNS events, and other adverse events were similar for both drugs.