Effect of intracavernosal sodium nitroprusside in impotence.

Recent studies have shown an important role for nitric oxide (NO) in cavernous smooth muscle relaxation. In this study the intracavernosal effects of the NO donor sodium nitroprusside (SNP) were investigated in 32 patients with erectile dysfunction. Erectile response and penile blood flow were investigated following intracavernosal administration of 360 micrograms SNP and 60 mg papaverine for diagnostic purposes. In all of 32 patients the erectile response to SNP was not better than that to papaverine. Haemodynamic evaluation of the deep penile arteries was carried out by colour duplex Doppler sonography after administration of SNP and papaverine. No differences in peak flow velocities were measured, but the increases in diameter and end-diastolic velocities were higher after SNP than after papaverine. Our data suggest that the NO donor SNP is not a new alternative agent for diagnosis and treatment of impotence.