The nitrogen oxide which as for this invention, pirazoropirimijinon chemical compound the prostate swollen symptom which includes as the active ingredient (BPH), the lower part urine road condition which relates with that (LUTS) being something regarding the preventive and remedy medicine, and the urethra smooth muscle or the prostate smooth muscle relaxation medicine, according to this invention, it was possible, was offered to offer nitrogen oxide by the fact that it obstructs PDE5 which disassembles c GMP relaxes the urethra smooth muscle or the prostate smooth muscle and it is possible to remedy the lower part urine road condition which attends by degrading urethra pressure, with the positive prostate swollen symptom and that. Furthermore, because as for the remedy medicine of this invention, the time when it arrives in density in the highest blood by comparison with the other PDE5 inhibiter being short, half-life is long, it is possible, to decrease the frequency of taking, it can use for the usefulness as the remedy medicine which is safe occurrence frequency of the side effect is low.本発明は、ピラゾロピリミジノン化合物を有効成分として含む前立腺肥大症(BPH)、それと係わる下部尿路症状(LUTS)の予防及び治療剤、及び尿道平滑筋または前立腺平滑筋弛緩剤に関するもので、本発明によると、c-GMPを分解するPDE5を阻害することで酸化窒素を提供することができ、提供された酸化窒素が尿道平滑筋または前立腺平滑筋を弛緩させて尿道圧を低めることにより、陽性前立腺肥大症及びそれにより随伴する下部尿路症状を治療することができる。さらに、本発明の治療剤は、他のPDE5阻害剤と比較して最高血中濃度に到達する時間が短くて半減期が長いので、服用回数を減らすことができ、副作用の発生頻度が低い安全な治療剤として有用に使用することができる。
