Naftopidil has affinity for both α1A- and α1D-adrenoreceptors for the treatment of benign prostatic obstruction and benign prostatic hyperplasia (BPH) associated with lower urinary tract symptoms (LUTS). It was originally developed as an α-adrenoceptor antagonistic anti-hypertensive drug. It has been evaluated in both prazosin-controlled and double-blind-controlled trials in Japan that verified dose-dependent effects, and therefore has had an indication for treatment of BPH in Japan, China, and South Korea. Several tamsulosin-controlled trials have suggested a potentially higher efficacy for alleviating storage symptoms with naftopidil. The optimal dose is 50-75mg per day according to characteristics including baseline IPSS. Well-designed randomized trials are warranted to confirm long-term outcomes regarding management of men with storage symptoms including nocturia, through comparisons of quality of life measures with other α-adrenergic blockers.
Reference: Hara N, Mizusawa T, Obara K, Takahashi K. The role of naftopidil in the management of benign prostatic hyperplasia. Ther Adv Urol 2013;5(2)111-119.