Hydrogen sulfide (H2S) poisoning remains a significant source of occupational fatalities and is the second most common cause of toxic gas-induced deaths. It is a rapidly metabolized systemic toxicant targeting the mitochondria, among other organelles. Intoxication is mostly acute, but chronic or in-between exposure scenarios also occur. Some genetic defects in H2S metabolism lead to lethal chronic H2S poisoning. In acute exposures, the neural, respiratory, and cardiovascular systems are the primary target organs resulting in respiratory distress, convulsions, hypotension, and cardiac irregularities. Some survivors of acute poisoning develop long-term sequelae, particularly in the central nervous system. Currently, treatment for H2S poisoning is primarily supportive care as there are no FDA-approved drugs. Besides hyperbaric oxygen treatment, drugs in current use for the management of H2S poisoning are controversial. Novel potential drugs are under pre-clinical research development, most of which target binding the H2S. However, there is an acute need to discover new drugs to prevent and treat H2S poisoning, including reducing mortality and morbidity, preventing sequalae from acute exposures, and for treating cumulative pathology from chronic exposures. In this paper, we perform a comprehensive review of H2S poisoning including perspectives on past, present, and future.
Keywords: Hydrogen sulfide poisoning; countermeasures; systemic toxicity; therapeutics; toxic mechanisms.