Agent for prevention and treatment of prostatic hyperplasia comprising pyrazolopyrimidinone compound

摘要

A composition comprising a pyrazolopyrimidinone compound is provided to lower the urethral pressure by inhibiting the activity of PDE-5 decomposing c-GMP and reduce the number of dosage due to a short time of reaching the maximum concentration in human blood and longer half life compared to other PDE5 inhibitors, thereby being able to safely treat benign prostatic hyperplasia and lower urinary tract symptoms accompanied thereby. An agent for preventing and treating benign prostatic hyperplasia or lower urinary tract symptoms comprises a pyrazolopyrimidinone compound(5-[2-propyloxy-5-(1-methyl-2-pyrolidinylethylamidosulphonyl)phenyl]-1-methyl-propyl-1,6-dihydro-7H-pyrazolo(4,3-d)pyrimidin-7-one) represented by the formula(1) as an effective ingredient. The agent is characterized in that it inhibits the PDE 5 activity but does not inhibit PDE 11 activity, the time of reaching the maximum concentration in human blood is 50-70 minutes and the half life is 9-15 hours.