Acute urinary retention secondary to benign prostatic hyperplasia. Effect of alpha-adrenergic blockade.

The alpha-adrenergic blocker phenoxybenzamine has been shown to be useful in the treatment of prostatism. To assess the place of phenoxybenzamine in the management of acute retention, 43 patients presenting with acute urinary retention secondary to benign prostatic hyperplasia were catheterized suprapubically. They were then randomized to receive either oral phenoxybenzamine (10 mg b.i.d.; n = 21), or placebo tablets (n = 22). Forty-eight hours later, the bladder of each patient was filled through the catheter with 300 ml sterile saline, the catheter was clamped, and the patient encouraged to void. Only 2 of 21 (10%) patients receiving phenoxybenzamine and 3 of 22 (14%) receiving placebo were able to void satisfactorily (p = NS). In this study phenoxybenzamine had no place in the management of acute retention of urine secondary to benign prostatic hyperplasia.