A randomized double-blind placebo-controlled multicentre study to explore the efficacy and safety of tamsulosin and tolterodine in women with overactive bladder syndrome

Objective To evaluate the efficacy of tamsulosin oral-controlled absorption system (OCAS) vs placebo in overactive bladder (OAB), to evaluate the safety and tolerability of once-daily dosing with tamsulosin OCAS, and to compare the efficacy and safety with tolterodine extended-release (ER). Patients and Methods A parallel-group, multicentre, multinational study was conducted with a single-blind placebo run-in period of 2 weeks, followed by a randomized, double-blind, double-dummy active and placebo-controlled treatment period of 6 weeks; women (aged 18-70 years) with symptoms of OAB for >= 3 months were recruited. Women were randomized to receive one of four doses of tamsulosin OCAS (0.25, 0.5, 1.0 or 1.5 mg), 4 mg of tolterodine ER, or placebo once daily for 6 weeks. The primary efficacy variable was the change in the mean number of voids/24 h. Secondary efficacy variables included change from baseline in; mean volume voided per void, mean number of incontinence episodes/24 h, mean number of urgency episodes/24 h and in quality of life (QoL), as assessed using the Kings Health Questionnaire (KHQ). Results Overall, 364 women were randomized; the primary efficacy analysis showed that the difference from placebo in the mean number of voids/24 h was not statistically significant for tamsulosin OCAS 1.5 mg (P = 0.189). There was no statistically significant difference for tolterodine ER 4 mg vs placebo in the mean number of voids/24 h (P = 0.353). Similarly, for the secondary outcome variables there was no statistically significant difference between tamsulosin and placebo. Although women taking tolterodine ER 4 mg had a consistently greater increase in mean voided volume/void and consistent decreases in incontinence episodes/24 h, urgency episodes/24 h and episodes of nocturia/24 h, this was not statistically significant. There was no significant improvement in QoL scores across the treatment groups. Tamsulosin OCAS was well tolerated and the proportion of women discontinuing because of adverse events was low (4.7%). Conclusion Tamsulosin is not effective for treating OAB in women and the evidence from this study does not support its use on an empirical basis.