USE OF AN ALPHA-1-BLOCKER, YM617, IN THE TREATMENT OF BENIGN PROSTATIC HYPERTROPHY

A recently synthesized α1-blocker, (R)(-)-5-[2-[[2-(o-ethoxyphenoxy)ethyl]amino]propyl]-2-methoxybenzenes ulfonamide hydrochloride (YM617), was evaluated in 270 patients with benign prostatic hypertrophy in a double-blind study. After 2 weeks on placebo the patients were assigned at random to 4 groups: group P-placebo, group L-0.1 mg., group M-0.2 mg. and group H-0.4 mg. of YM617. Comparing the placebo to the treatment period, subjective symptoms, such as nocturia and urgency, were significantly decreased in group H (p < 0.01). The sensation of incomplete voiding was significantly improved in groups M and H (p < 0.01). However, the differences among the groups were statistically insignificant. Residual urine volume was significantly decreased in groups L, M and H after instillation of saline into the bladder (p < 0.01) but not in group P. The maximum and average flow rates were significantly increased in groups L, M and H (p < 0.01) but not in group P. Average flow rate showed significant differences between groups M or H versus group P. Neither orthostatic hypotension nor a decrease in blood pressure was noted. Adverse side effects and changes in laboratory data were all slight and disappeared when the second tests were performed. In summary, the irritative and obstructive oms caused by benign prostatic hypertrophy was decreased and urodynamic studies were markedly improved by the α1-blocker, YM617. The drug seems to be useful in the treatment of patients with benign prostatic hypertrophy.