Sodium thiosulfate for acute cyanide poisoning: study in a rat model

Unlike practices in the United States where it is associated with other antidotes, sodium thiosulfate is not used for emergency therapy for cyanide poisoning in France. The purpose of this study was to develop a rat model using intraperitoneal injections of sodium thiosulfate at a dose of 225 mg/kg to test its therapeutic efficacy for acute cyanide poisoning. Efficacy was assessed directly by quantifying arterial blood cyanide and indirectly using markers of hypoxia: serum lactate and arteriolization of venous blood gases. Cyanide poisoning induced intense biological anomalies which were persistent (serum lactate) or transient (blood gases). Sodium thiosulfate was found to be an effective antidote in the rat enabling rapid normalization of hypoxia markers and clearing of cyanide from arterial blood.