EFFECT OF NAFTOPIDIL ON URETHRAL OBSTRUCTION IN BENIGN PROSTATIC HYPERPLASIA - ASSESSMENT BY URODYNAMIC STUDIES

Thirty-two patients with voiding dysfunction attributable to symptomat ic benign prostatic hyperplasia were treated with naftopidil, an alpha (1)-blocker, at doses of 25-75 mg/day for 4-6 weeks. The efficacy of t he drug was assessed from the changes in urinary symptoms and urodynam ic data. Total symptom scores were significantly reduced after treatme nt (P<0.001). Average flow rate and maximum flow rate were significant ly increased (P<0.001 and P<0.001, respectively), and residual urine v olume, residual urine rate (ratio of residual urine volume/sum of void ed volume and residual urine volume), and maximum urethral closure pre ssure were significantly (P<0.05, P<0.01, and P<0.05, respectively) re duced, and at bladder capacity, the first desire to void was significa ntly (P<0.05) increased. The pressure/ flow study demonstrated no chan ges in intravesical pressure at maximum flow, but a significant (P<0.0 5) reduction in minimum urethral resistance. A mild side effect (dizzi ness) was noted in one patient (3.3%), which soon disappeared after th e dose was decreased. The efficacy was good or excellent in 21 of 30 p atients (70.0%). The drug was evaluated to be promising in the treatme nt of bladder outlet obstruction due to benign prostatic hyperplasia. (C) 1994 Wiley-Liss, Inc.