NITRITE AND THIOSULFATE THERAPY IN CYANIDE POISONING

Abstract

In 1932 Geiger¹ began to use methylene blue in treatment of cyanide poisoning. The antidotal action of the dye was shown by Wendel² and Hug³ to be due to the formation of methemoglobin, which successfully competes with the respiratory enzyme, ferricytochrome oxidase, for cyanide ions. Subsequent reports⁴ indicate that methylene blue is not an efficient antidote because it is a poor methemoglobin former and at the same time reverses the reaction in presence of co-enzyme.⁵ In fact, the dye is of greater value in the treatment of methemoglobinemia⁶ than in cyanide poisoning. Nevertheless, the trial of methylene blue stimulated a renewed search for cyanide antidotes, and led to the discovery of a more effective therapy. Independent investigations in Argentina⁷ and the United States^4a gave rise to a clear-cut conclusion that the combination of sodium nitrite and sodium thiosulfate, consecutively injected by vein,