Objective: To assess the efficacy, incidence of dry mouth and overall satisfaction with initial doses of 5, 10 and 15 mg of a new, once-daily, controlled-release (CR) form of oxybutynin for treating urge urinary incontinence (UUI).
Patients and methods: Patients who reported urinary incontinence (UI) (one or more episodes/diary) and voiding frequency (eight or more voids/day) or urgency (one or more episodes/diary) during a 2-week baseline were randomized to once-daily 5, 10 or 15 mg CR oxybutynin for 4 weeks. Daily episodes of UI, voids, urgency, adverse events, dry mouth and satisfaction were recorded in a 3-day diary at baseline and after 4 weeks of treatment. In all, 237 patients were randomized and evaluated.
Results: Episodes of UI, voids and urgency were significantly reduced over the study period at all doses. Daily UI episodes were significantly lower with 15 mg/day than 5 and 10 mg/day. Dry mouth symptoms were similar in the 10 and 15 mg/day groups, and higher than in the 5 mg/day group. However, significantly greater overall satisfaction was reported with 15 than 5 mg/day.
Conclusions: There were significant dose-response relationships with CR oxybutynin for both UI episodes and dry mouth. The greatest satisfaction was with 15 mg/day, and the severity of dry mouth was comparable at 10 mg/day, indicating that greater efficacy at the higher dose did not compromise tolerability.