Further investigations regarding the toxicity of sodium nitroprusside

Sodium nitroprusside is a valuable vasodilator, but its use has been curtailed because of numerous reports that, in the presenceof blood,nitroprussidedecomposeswithreleaseof toxic cyanide. We have examined the release of cyanide in terms of the known chemistry of nitroprusside and suggest that photochemicaldecompositionof nitroprussideand (or) its metabolism in vivo invalidates the analytical procedure used by previous workers. We also present evidence for the stability of nitroprussidein blood, based on 13C nuclear magnetic resonancestudies. Additional Keyphrases: cyanide- nuclear magnetic reso-nance- analyticalerror Sodium mtroprusside (Na2[Fe(CN)5N01) is a valuable vasodilator for use in hypertensive emergencies, induced hypotension, and the management of myocardial infarction