[The therapeutic scope of sodium nitroprusside]

Sodium nitroprusside (SNP) as a monoinfusion was administered to 50 patients for periods of a few hours. A further group of 20 patients received SNP for periods of several days as a combination solution, of SNP mixed with sodium thiosulphate. Infusion of SNP on its own at levels exceeding 2 micrograms/kg/min led to cyanide levels in the blood rising proportional to dosage. Infusion of SNP mixed with thiosulphate showed no such accumulation. This procedure is free of danger and should become the technique of choice when therapeutically administering SNP to lower blood pressure.