| 摘要 |
<p>A pyridopyrimidine or a naphthyridine derivative of the formula (I): <CHEM> wherein R<1> is an optionally substituted nitrogen-containing heterocyclic group, etc.; R<2> is H or a lower alkyl group; R<3> is H or an optionally substituted lower alkyl group, etc.; R<4> is H, a lower alkyl group, COOH, etc.; R<5> is H, an optionally substituted aryl, etc; one of X and Y is CH and the other is nitrogen, or both of X and Y are nitrogen; or a pharmaceutically acceptable salt thereof, these compounds exhibiting excellent PDE V inhibitory activities, and being useful in the prophylaxis or treatment of penile erectile dysfunction, etc.</p> |
