title: Early Efficacy of an α1 Adrenoceptor Antagonist, Naftopidil, against Lower Urinary Tract Symptoms Suggestive of Benign Prostatic Hyperplasia.
abstract: OBJECTIVE
  The present study investigated the early efficacy of naftopidil against lower urinary tract symptoms (LUTS) suggestive of benign prostatic hyperplasia (BPH).
  
  
  METHODS
  Subjects comprised patients with LUTS suggestive of BPH who were followed prospectively for 8 weeks. Inclusion criteria were: (i) international prostate symptom score (IPSS) ≥8; (ii) no previous treatment for BPH; and (iii) eligibility for naftopidil monotherapy. IPSS and quality of life index were evaluated, and uroflowmetry and residual urine volume were determined optionally. In the previous study, patients who demonstrated a decrease in total American Urological Association symptom score of 25% or more from baseline were considered responders. The ratio of onset of efficacy of naftopidil was calculated by the ratio of the number of responder in each group with the starting dose.
  
  
  RESULTS
  Naftopidil efficacy was analyzed for 243 patients. Significant improvement of IPSS was achieved within 1-3 days after medication. Starting dosage and average dosage were identified as factors associated with the period until onset of naftopidil efficacy. Onset of efficacy was significantly quicker with a starting dosage of 50 mg/day as compared with 25 mg/day (P = 0.0047). However, ratios of onset of efficacy with starting dosages of 25, 50 and 75 mg/day were 77.9, 76.7 and 85.7%, respectively, showing no significant difference between groups (P = 0.7463). Duration to onset of efficacy with naftopidil dosage ≥50 mg/day was 11.2 days, significantly early compared to dosage <50 mg/day. Incidence of adverse effect was 3.8%.
  
  
  CONCLUSIONS
  Naftopidil showed early effects against LUTS suggestive of BPH within a few days.
authors.affiliation: Department of Urology, Shinshu University School of Medicine, Matsumoto, JapanDepartment of Urology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Chuo, JapanDepartment of Urology, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Ishizuka
authors.affiliation: Department of Urology, Shinshu University School of Medicine, Matsumoto, JapanDepartment of Urology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Chuo, JapanDepartment of Urology, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Osamu
authors.initials: O
authors.lastname: Nishizawa
authors.affiliation: Department of Urology, Shinshu University School of Medicine, Matsumoto, JapanDepartment of Urology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Chuo, JapanDepartment of Urology, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Takeda
authors.affiliation: Department of Urology, Shinshu University School of Medicine, Matsumoto, JapanDepartment of Urology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Chuo, JapanDepartment of Urology, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Teruhisa
authors.initials: T
authors.lastname: Nomura
authors.affiliation: Department of Urology, Shinshu University School of Medicine, Matsumoto, JapanDepartment of Urology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Chuo, JapanDepartment of Urology, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Japan.
authors.forename: Susumu
authors.initials: S
authors.lastname: Kagawa
keywords: benign prostatic hyperplasia; lower urinary tract symptoms; naftopidil; α1 blocker