In a prospective multicentric double-blind trial, urapidil, an alpha 1-adrenergic antagonist, was investigated for its efficacy in benign prostatic hypertrophy (BPH). After 1 week of baseline on placebo, 214 patients with BPH were randomly assigned to 4 groups; group P was given placebo, group L, 15 mg of urapidil b.i.d. for 3 weeks, group M, 15 mg b.i.d. for 1 week followed by 30 mg b.i.d. for 2 weeks, and group H, 15 mg b.i.d. for 1 week followed by 45 mg b.i.d. for 2 weeks. In all groups, day and night urinary frequency improved significantly (p < 0.01 or p < 0.05) compared to baseline, but the differences were not significant between groups. The residual urine rate was significantly (p < 0.05 vs. group P) decreased in group H. Average and maximum flow rate improved significantly (p < 0.01 or p < 0.05) in group M and group H, but intergroup differences were not noted. Overall impression evaluated by investigators improved significantly (p < 0.01 vs. group P) in group M and group H. More patients in group H (7/55) and group M (4/51) had side effects than in group P (2/54). None of them were severe. In summary, a daily dosage of 60 mg urapidil proved to be the most beneficial in the treatment of patients with BPH.
