NITRITE AND THIOSULFATE THERAPY IN CYANIDE POISONING

In 1932 Geiger1began to use methylene blue in treatment of cyanide poisoning. The antidotal action of the dye was shown by Wendel2and Hug3to be due to the formation of methemoglobin, which successfully competes with the respiratory enzyme, ferricytochrome oxidase, for cyanide ions. Subsequent reports4indicate 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.5In fact, the dye is of greater value in the treatment of methemoglobinemia6than 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 Argentina7and the United States4agave rise to a clear-cut conclusion that the combination of sodium nitrite and sodium thiosulfate, consecutively injected by vein,