Temperature dependent release of cyanide from sodium nitroprusside

The effect of temperature on the release of cyanide from sodium nitroprusside (SNP), a potent vasodilating drug, was studied in vitro. It was observed that higher temperatures accelerate the degradation rate of SNP and facilitate the formation of cyanmethemoglobin in blood. The results indicate that hypothermia which is often used in combination with SNP may reduce the incidence of cyanide toxicity by slowing the degradation of SNP.