H 2 S in Critical Illness-A New Horizon for Sodium Thiosulfate?

Ever since the discovery of endogenous H 2 S and the identification of its cytoprotective properties, efforts have been made to develop strategies to use H 2 S as a therapeutic agent. The ability of H 2 S to regulate vascular tone, inflammation, oxidative stress, and apoptosis might be particularly useful in the therapeutic management of critical illness. However, neither the inhalation of gaseous H 2 S, nor the administration of inorganic H 2 S-releasing salts or slow-releasing H 2 S-donors are feasible for clinical use. Na 2 S 2 O 3 is a clinically approved compound with a good safety profile and is able to release H 2 S, in particular under hypoxic conditions. Pre-clinical studies show promise for Na 2 S 2 O 3 in the acute management of critical illness. A current clinical trial is investigating the therapeutic potential for Na 2 S 2 O 3 in myocardial infarct. Pre-eclampsia and COVID-19 pneumonia might be relevant targets for future clinical trials.