Symptoms Predictive for Efficacy of Naftopidil in Patients with Benign Prostate Hyperplasia

Objectives: To evaluate the lower urinary tract symptoms predicting the efficacy of the α1‐adrenoreceptor (AR) antagonist naftopidil in patients with benign prostate hyperplasia. Methods: The efficacy of naftopidil was examined on the basis of changes in the international prostate symptom score (IPSS). All patients received naftopidil (50 mg/day) for 12 weeks. We defined a “responder” as a patient whose total IPSS improved by five or more points and assessed the lower urinary tract symptoms predicting the efficacy of treatment by performing multivariate and probit analyses. Results: Among 132 patients whose data could be analyzed, the efficacy rate was 50.8%. All IPSS items except the urgency score were significantly higher in the responders than the non‐responders before treatment, and all IPSS items were lower in the responders after treatment. In the responder group, significant improvements were observed in the total IPSS score, quality of life (QOL) index, maximum flow rate (Q_max), residual urine volume, and all IPSS items after treatment. In contrast, in the non‐responder group, no parameter except the QOL index improved significantly. The probit analysis demonstrated that the score for weak stream (≥3) or nocturia (≥4) in the IPSS were factors predicting an effective response to naftopidil treatment. Conclusions: Weak stream and/or nocturia are the key symptoms that predict the efficacy of naftopidil treatment in patients with benign prostatic hyperplasia. Those with a score of ≥3 for weak stream or of ≥4 for nocturia are expected to achieve a good response in the subjective symptoms with administration of naftopidil.