Effect of KT-611 (Naftopidil) on the contraction of human prostatic tissue and its use in benign prostatic obstruction

良性前立腺肥大症49例で1日1或いは2回本剤を投与した所, 自・他覚的症状は有意に改善された.残尿量及び残尿率は有意に減少した.平均及び最大尿流量率は有意に増加した.適正量は, 1日1回, 25～75 mg, 或いは1日2回, 25～100 mgと思われた.有害反応及び異常な臨床検査所見は軽度であった
A new alpha 1-adrenergic receptor antagonist, KT-611 (naftopidil) antagonized dose dependently the contraction induced by agonists, noradrenaline and phenylephrine in the human prostatic tissue. KT-611 at a dosage of once or twice a day was evaluated for its effects on 49 patients with benign prostatic hypertrophy. The drug improved subjective and objective symptoms significantly. The residual urine was reduced in volume and percentage significantly. The average and maximum flow rates increased significantly. The optimal dosage was presumed to be in the range of 25 to 75 mg once a day or 25 to 100 mg twice a day. Adverse reactions and abnormal laboratory findings were all slight. KT-611 was concluded to be useful in the treatment of patients with benign prostatic hypertrophy.