A double-blind trial on the effect of bunazosin hydrochloride for the symptoms of benign prostatic hypertrophy]

A multicenter clinical trial was carried out on 372 patients in double-blind conditions in order to determine the clinical effects of Ea-0643 (bunazosin hydrochloride) on voiding disorders in benign prostatic hypertrophy, compared with paraprost and placebo. Of the 372 patients, 129 were assigned to bunazosin hydrochloride, 118 to paraprost and 125 to placebo. The improvement rating for all five subjective symptoms improved with passage of time in all the bunazosin hydrochloride, paraprost and placebo groups. A higher improvement rating was obtained in the bunazosin hydrochloride group for retarded urination, urinary stream condition and abdominal pressure at voiding, while the improvement rating was higher for prolonged urination in the placebo group and for residual urine in the paraprost group, but there was no significant difference in improvement ratings between the groups. The daily frequency of voiding decreased to a significant extent in the bunazosin hydrochloride and placebo group at week 1, and there was a significant difference between the bunazosin hydrochloride and the paraprost groups and between the placebo and the paraprost groups. The improvement rating for conditions of voiding was higher with the bunazosin hydrochloride group, when "slightly or better improved" cases were taken into account, but there was no difference between the groups. As for objective symptoms, maximum and average flow rate, useful measures for clinical evaluation of drug effects on voiding disorders, were significantly increased, with a decrease to match in residual urine ratio in the bunazosin hydrochloride group. In terms of maximum and average flow rate bunazosin hydrochloride was significantly superior to paraprost at weeks 1 and 2 and superior to placebo at weeks 2 and 4 and at the final evaluation as well. In terms of residual urine ratio bunazosin hydrochloride was superior to both paraprost and placebo. The global improvement rating, as assessed by the U- and chi 2-tests, was significantly higher in the bunazosin hydrochloride group than in the paraprost group, and there was a significant difference in global improvement ratings, as assessed by the chi 2-test, between the placebo and the paraprost groups, when "moderately or better improved" cases were taken into account. The stratified analysis of the prostate glands, subjective symptoms, maximum flow rate and residual urine ratio revealed that in patients with more advanced conditions the bunazosin hydrochloride group showed significantly superior improvement rates than the paraprost and placebo groups.(ABSTRACT TRUNCATED AT 400 WORDS)