Effect of antagonists on the physiologic disposition of sodium cyanide

Attempts were made to evaluate the effects of pretreatment with air and oxygen either alone or in various combinations with sodium nitrite and/or sodium thiosulfate on the physiological disposition of 14C-labeled sodium cyanide in mice. The radioactive respiratory excretion was studied by radiorespirometry, and the effects of various combinations of cyanide antagonists were compared. Oxygen either alone or in combination with sodium thiosulfate significantly enhanced the respiratory excretion when compared with air. Sodium thiosulfate accelerated the initial rate, but not the total amount of radioactivity excreted. The cumulative recovery of radioactive gases was significantly greater with groups receiving oxygen either alone or with sodium thiosulfate. When sodium nitrite was employed as an antidote either alone or with sodium thiosulfate, no difference in the respiratory excretion was noted between air and oxygen. The use of the sodium nitrite-sodium thiosulfate combination either with air or oxygen resulted in a marked decrease in the initial rate as well as the total amount of respiratory radioactivity excreted. No significant differences between various experimental groups were noted in the total amount of urinary radioactivity excreted or the total body retention of radioactivity.