前立腺肥大症に対するα1ブロッカー単独療法およびα1ブロッカーとアンチアンドロゲン剤併用療法の無作為長期比較試験の検討 ―I-PSS改善効果を中心に―

Abstract

αブロッカーと酢酸クロルマジノンとの併用療法は, インポテンス発現の可能性に留意する必要があるが, 自覚症状の早期改善が認められ, さらに16週以降, 長期に継続投与することで, 閉塞症状および最大尿流量率の改善が期待できることが示唆された

This study was conducted to examine the efficacy of administration of tamsulosin hydrochloride alone or in combination with chlormadinone acetate (CMA) against lower urinary tract symptoms for a period of 52 weeks in 33 patients with benign prostatic hyperplasia. The patients were randomly allocated into a group administered tamsulosin alone and a group administered tamsulosin in combination with CMA. Based on the assessment of the total I-PSS (International Prostate Symptom Score), significant symptomatic improvement was noted 4 weeks after the commencement of drug administration in the tamsulosin + CMA group, whereas no significant improvement was observed in the tamsulosin group. Both irritative and obstructive bladder symptoms improved significantly at any time of assessment after 4 weeks of drug administration in the tamsulosin + CMA group; however, significant improvement was noted only at week 16 and week 52 for irritative symptoms and at week 16 for obstructive symptoms in the tamsulosin group. In particular, obstructive symptoms showed significant improvement at week 4 in the tamsulosin + CMA group, as compared with that in the tamsulosin group. The average value of peak urinary flow rate was significantly increased in the tamsulosin + CMA group (10.4 ml/s to 15.6 ml/s) as compared with that in the tamsulosin group (8.5 ml/s to 10.5 ml/s). These findings indicate that combined administration of tamsulosin and CMA resulted in early improvement of lower urinary tract symptoms in these patients. Long-term combined administration of tamsulosin and CMA thus appears to be a promising treatment strategy for the improvement of obstructive symptoms and peak urinary flow rate, particularly, 16 weeks onward after administration in patients with benign prostatic hyperplasia.