[The evaluation of the effects of bunazosin hydrochloride in the treatment of prostatic hyperplasia]

Thirty-five patients with prostatic hyperplasia were entered into a randomized controlled study using bunazosin hydrochloride(alpha 1-adrenergic blocker). Eighteen patients were allocated to be treated with an initial dose of 1.5 mg/day (group 1) and 17 patients received an initial dose of 3.0 mg/day (group 2). Subjective symptoms and parameters of urodynamic studies were evaluated after 4 weeks and 12 weeks. There were 5 withdrawals or exclusions within 4 weeks and 6 within 12 weeks. Therefore, 15 patients in group 1 and 15 patients in group 2 were eligible for evaluation at 4 weeks, 12 patients in group 1 and 11 patients in group 2 were eligible for evaluation at 12 weeks. The rates of the improvement in subjective symptoms such as retarded urination, protracted urination, weakened urinary stream, abdominal straining on voiding, and sense of residual urine were 40%, 25% in group 1 and 46.7%, 36.4% in group 2, at 4 weeks and at 12 weeks, respectively. The rate of improvement in objective parameters of the urodynamic study such as voiding volume, residual volume, maximum flow rate and average flow rate were 26.7%, 16.7% in group 1 and 26.7%, 20.0% in group 2, at 4 weeks and at 12 weeks, respectively. Thus, these improvements were not correlated with the dosage of drug. Adverse effects such as diarrhea, mild headache, palpitation and gastric disturbance were observed in 2 patients in group 1, and 3 patients in group 2. In the 24 patients treated with the drug over 12 weeks, there were no specific adverse effects due to prolonged administration. These findings showed that bunazosin hydrochloride is beneficial for the treatment of prostatic hyperplasia, and could be safety administered for a prolonged period of time up to 12 weeks.