A Multicenter Placebo-Controlled, Double-Blind Trial of Urapidil, an α-Blocker, on Neurogenic Bladder Dysfunction

Abstract

Objectives: To assess the efficacy of urapidil, an α-blocker, on neurogenic bladder dysfunction in a placebo-controlled, double-blind trial. Methods: 149 patients were randomly assigned to receive a placebo or 60 mg/day of urapidil for 4 weeks. The evaluation of efficacy included changes in urinary symptom scores and the results of a pressure/flow study. Results: There were significant intergroup differences with regard to straining and the sum of urinary symptom scores, with the urapidil group showing marked improvements (p = 0.016 and p = 0.011, respectively). In the urapidil group, the average and maximum flow rates were unchanged, but the residual urine volume decreased significantly (p < 0.001) as compared with the baseline value. The pressure at maximum flow and the minimum urethral resistance decreased significantly (p = 0.040 and p = 0.040, respectively) in the urapidil group, and there was a significant (p = 0.005) inter-group difference with regard to pressure at maximum flow. There was also a significant (p < 0.001) inter-group difference with regard to the overall therapeutic effect. Side effects were noted in 2 patients treated with urapidil and 6 in the placebo group. Conclusion: Urapidil is effective for the treatment of voiding dysfunction in patients with neurogenic bladder.