Bladder outflow obstruction treated with phenoxybenzamine.

Sixty-one male patients took part in a study of phenoxybenzamine (PBZ), the initial phase of which was double-blind (41 patients). All patients had urodynamically proven outflow obstruction. The double-blind phase of the trial showed an overall symptomatic improvement in the PBZ patients. The symptoms of slow stream and hesitancy were significantly improved. The urethral pressure profile features of prostatic plateau height and prostatic plateau area were significantly decreased in the PBZ group. Dizziness was the most common side effect of PBZ but was well tolerated by most patients. This study shows that PBZ has an effect on bladder outflow obstruction by reducing pressure in the proximal urethra and that the drug is suitable for the treatment of patients with symptoms attributable to obstruction.