Efficacy of Additional Dutasteride on Lower Urinary Tract Symptoms in Patients with Alpha-1 Blocker-Resistant Benign Prostatic Hyperplasia


Correspondence: Atsushi Sengiku, MD, Department of Urology, Japanese Red Cross Otsu Hospital, 1-1-35, Nagara, Otsu, Shiga 520-8511, Japan. Tel: +81-77-522-4131; Fax: +81-77-525-8018. Email: sengiku@kuhp.kyoto-u.ac.jp


Objective: We investigated the effects of dutasteride on urination and quality of life (QOL) in patients diagnosed with benign prostatic hyperplasia (BPH) who showed poor improvement in lower urinary tract symptoms (LUTS) with alpha-1 blockers.

Methods: We retrospectively analyzed 108 patients with BPH who took dutasteride for more than 3 months from October 2009 to October 2011. The patients showed poor improvement in LUTS despite administration of alpha-1 blockers for more than 3 months; all had an International Prostate Symptom Score (IPSS) of eight or greater. We investigated changes in prostate-specific antigen and prostate volume and performed uroflowmetry and medical interviews to assess IPSS-QOL score and BPH impact index (BII).

Results: Mean prostate volume was 52.8 ± 22.2 mL, and the mean period of dutasteride administration was 284 ± 118 days. Prostate volume decreased 24.1% from baseline to 6 months after administration. Voiding symptoms and storage symptoms showed improvements with longer administration periods, but only nocturia showed no clear improvement. There was a 0.9-point decrease in BII after 6 months. There was no statistically significant association between the rate of prostate volume reduction and improvement in voiding and storage symptoms.

Conclusion: Additional administration of dutasteride to patients with alpha-1 blocker-resistant BPH led to improvements in all voiding and storage symptoms except nocturia, and showed no correlation between the prostate volume reduction rates and improvement in LUTS.