A Randomized Study Comparing Once-Daily and Thrice-Daily Naftopidil 75 mg/Day for Lower Urinary Tract Symptoms of Benign Prostatic Hyperplasia

Background: The efficacy and tolerability of naftopidil 75 mg administered once daily (OD) in the evening (g roup O) were compared to those of naftopidil 25 mg thrice daily (TID), given in the morning, afternoon and evening (g roup T), for lower urinary tract symptoms associated with benign prostatic hyperplasia (LUTS/BPH). The factors predicting the efficacy of each dosage regimen were also examined. Methods: The participants were 101 patients with LUTS/BPH who were randomly administered naftopidil for 8 weeks in either group O or group T. Inclusion criteria were international prostate symptom score (IPSS) greater than or equal to 8 and IPSS quality of life (IPSS-QoL) greater than or equal to 3. Results: IPSS total score, IPSS-QoL and the BPH impact index were all significantly improved compared to baseline for both groups at 8 weeks after treatment. Voided volume, maximum flow rate and average flow rate were significantly improved compared to baseline only for group O at 8 weeks after treatment. The effectiveness rate based on the criteria for treatment efficacy of the Japanese clinical practice guideline for voiding dysfunction was not significantly different between the two groups. There was no independent predictive factor for the efficacy of naftopidil in group O, but prostate volume and symptom severity were identified as predictive factors in group T. The rate of adverse events was not significantly different between the two groups. Conclusions: The overall efficacy of naftopidil 75 mg/day given OD was approximately equal to that of 75 mg/day TID, but OD therapy was objectively more effective. LUTS/BPH patients with large prostate volume should be given OD therapy because the therapy is not affected by the severity of subjective symptoms or prostate volume. World J Nephrol Urol. 2014;3(2):72-82 doi: http://dx.doi.org/10.14740/wjnu169e