has role independent continuant antiviral agent renoprotective agent antifibrotic agent piperazines antibacterial agent sulfonamide hypoglycemic agent antineoplastic agent vasodilator agent antihypertensive agent pyrazolopyrimidine antiglaucoma drug antiparkinson drug anti-ulcer drug antispasmodic drug hepatoprotective agent neuroprotective agent EC 3.1.4.35 (3',5'-cyclic-GMP phosphodiesterase) inhibitor anti-anaemic agent sildenafil A pyrazolo[4,3-<em>d</em>]pyrimidin-7-one having a methyl substituent at the 1-position, a propyl substituent at the 3-position and a 2-ethoxy-5-[(4-methylpiperazin-1-yl)sulfonyl]phenyl group at the 5-position. CHEBI:9139