日本人男性の前立腺肥大症に対するデュタステリドの至適用量の検討ランダム化，二重盲検，プラセボ対照，並行群間，用量反応試験

Abstract

The efficacy, safety and recommended dose of dutasteride on Japanese men with benign prostatic hyperplasia (BPH) have been assessed in a randomized, double-blind, placebo-controlled, parallel-group study. A total of 284 patients with BPH were randomized to dutasteride (0.05, 0.5 or 2.5 mg) or placebo once daily for 24 weeks. At week 24, the 0.5 mg dose of dutasteride decreased serum dihydrotestosterone (DHT) levels by approximately 90% and reduced prostate volume by approximately 25%, comparable with the highest dose of dutasteride 2.5 mg. In addition, dutasteride 0.5 mg significantly improved International Prostate Symptom Score (IPSS) and Qmax compared to placebo. These results show that 0.5 mg appears to be the lowest dose at which DHT was almost completely suppressed, together with a substantial reduction of prostate volume. Dutasteride was generally well tolerated throughout 24 weeks therapy. Given the above, 0.5 mg has been chosen as the recommended dose in Japanese men with BPH.