Introduction and hypothesisTo confirm the efficacy and tolerability of extended release (ER) trospium chloride in women with overactive bladder syndrome (OAB), data from two identical phase III studies were analyzed.MethodsAdults (aged ≥ 18 years) who had OAB with urinary urgency, frequency, and urge urinary incontinence (UUI) were randomized to trospium ER 60 mg or placebo once daily for 12 weeks. The analysis included 989 women (trospium ER, n = 484; placebo, n = 505). Endpoints examined included changes from baseline in number of toilet voids and UUI episodes/day at week 12. Continuous data were analyzed using rank analysis of variance.ResultsAt week 12, significantly greater mean reductions in numbers of toilet voids and UUI episodes/day occurred with trospium ER versus placebo (P < 0.0001). Adverse events considered at least possibly related to treatment with trospium ER included dry mouth (11.4%) and constipation (8.9%).ConclusionsTrospium ER was effective and well tolerated in women with OAB.