In this double-blind, placebo-controlled trial, we assessed the efficacy and tolerability of solifenacin treatment for overactive bladder (OAB) with a focus on urgency-related endpoints. Changes in number of urgency episodes were evaluated as the primary endpoint; secondary endpoints included changes in conventional diary-based OAB symptoms. We also measured warning time (defined as the time from first sensation of urgency to voiding).

We randomized patients (n = 739) to once-daily solifenacin or placebo for 12 weeks. Solifenacin 5 mg or matching placebo was administered for 4 weeks; dose could be maintained or adjusted at weeks 4 and 8. Participants completed 3-day micturition diaries at multiple study visits; warning time was recorded at baseline and week 12.

At study end, the mean number of urgency episodes per 24 hours decreased by 3.91 (from 6.15 to 2.24) with solifenacin and by 2.73 (from 6.03 to 3.30) with placebo (P < .0001 between groups). Other diary-recorded symptoms (incontinence and micturition frequency) were also significantly more reduced with solifenacin compared with placebo. Median warning time increased 31.5 seconds (baseline, 67.8 seconds) with solifenacin, significantly longer (P = .008) than the median increase of 12.0 seconds (baseline, 65.0 seconds) observed with placebo.

Solifenacin treatment significantly reduced episodes of urgency and other key symptoms of OAB. Solifenacin is the first antimuscarinic to demonstrate significant warning time improvement at approved dosing, as shown in a large OAB study population. This is the largest OAB clinical trial yet conducted to evaluate warning time and diary variables in the same study population.