Sodium thiosulfate is scientifically validated as an antidote specifically for cyanide poisoning. Its primary mechanism involves acting as a sulfur donor, enabling the enzymatic conversion of toxic cyanide to the much less toxic thiocyanate, which is then excreted in urine. This role is well established in toxicology and emergency medicine texts and is included in guidelines for the management of cyanide poisoning, such as those published by the World Health Organization and various national poison centers.

While sodium thiosulfate’s most prominent use is for cyanide toxicity, it is sometimes employed in combination with other agents like sodium nitrite. Clinical evidence supporting its efficacy comes from animal studies, case reports, and human observational studies, as randomized controlled trials in acute poisoning are rare for ethical and practical reasons. Nonetheless, its biochemical mechanism is clear and its use is standard practice in settings where cyanide exposure is a risk (e.g., smoke inhalation, industrial accidents).

There is less evidence for its use in other types of chemical poisoning, and it is not generally recommended for toxins other than cyanide. Thus, while not universally applicable for all chemical poisonings, its use for cyanide poisoning is both scientifically justified and widely accepted in clinical practice.