A comprehensive review of treatments for hydrogen sulfide poisoning: past, present, and future.

Hydrogen sulfide (H 2 S) 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 H 2 S metabolism lead to lethal chronic H 2 S 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 H 2 S poisoning is primarily supportive care as there are no FDA-approved drugs. Besides hyperbaric oxygen treatment, drugs in current use for the management of H 2 S poisoning are controversial. Novel potential drugs are under pre-clinical research development, most of which target binding the H 2 S. However, there is an acute need to discover new drugs to prevent and treat H 2 S 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 H 2 S poisoning including perspectives on past, present, and future.