The effect of urapidil on neurogenic bladder: a placebo controlled double-blind study

We assessed the efficacy and safety of urapidil, a new alpha-blocker, for the treatment of neurogenic bladder dysfunction in a prospective double-blind trial.

A total of 136 patients was randomly assigned to receive placebo (group 1), or treatment with 30 mg. of urapidil for 4 weeks (group 2) or 30 mg. for 2 weeks followed by 60 mg. for 2 weeks (group 3).

Urinary frequencies decreased significantly only in group 3. The sum of obstructive symptom scores decreased significantly in all groups. However, a significant difference in subjective symptoms was not noted among the groups. Average and maximum flow rates, and residual urine improved significantly in groups 2 and 3 but not in group 1. Regarding cystometric parameters, no significant changes were noted in any group. In the pressure-flow study, the pressure at maximum flow rate and minimum urethral resistance (pressure at maximum flow rate divided by the square of maximum flow rate) decreased significantly only in group 3. In the urodynamic assessment, significant improvement was noted in groups 3 versus 1. There were no significant differences between the sexes or among underlying diseases with regard to symptomatic and urodynamic improvements. Side effects were noted in 2 patients in group 3 and 1 in group 2, none of which was severe.

Urapidil improved voiding dysfunction in patients with a neurogenic bladder and decreased urethral resistance in a dose related fashion.