Intramuscular aminotetrazole cobinamide as a treatment for inhaled hydrogen sulfide poisoning in a large swine model. Issue 1 (31st March 2020) - Hendry‐Hofer, Tara B.
Abstract: Hydrogen sulfide (H2 S), a high‐threat chemical agent, occurs naturally in a variety of settings. Despite multiple incidents of exposures and deaths, no FDA‐approved antidote exists. A rapid‐acting, easy to administer antidote is needed. We conducted a randomized control trial in swine comparing intramuscular administration of aminotetrazole cobinamide (2.9 mL, 18 mg/kg) to no treatment following inhalation of H2 S gas. We found that aminotetrazole cobinamide administered 2 min after the onset of respiratory depression—defined as a tidal volume of less than 3 mL/kg for 2 consecutive minutes—yielded 100% survival, while all control animals died. Respiratory depression resolved in the treatment group within 3.6 ± 1.5 min (mean ± SD) of cobinamide administration, whereas control animals had intermittent gasping until death. Blood pressure and arterial oxygen saturation (SO2 ) returned to baseline values within 5 and 10 min, respectively, of cobinamide treatment, and plasma lactate concentration decreased to less than 50% of the highest value by the end of the experiment. In control animals, plasma lactate rose continuously until death. We conclude that intramuscular aminotetrazole cobinamide is effective in a large animal, inhalational model of acute, severe H2 S poisoning. Abstract : To evaluate the efficacy of aminotetrazole cobinamide against inhaled hydrogen sulfide (H2 S), we exposed large swine ( Sus scrofa, 30−40 kg) to H2 S gas. Our objective was to determine if intramuscular aminotetrazole cobinamide would improve survival and clinical outcome in swine following high‐dose inhalational exposure to H2 S. We conclude that intramuscular administration of aminotetrazole cobinamide improves survival and clinical outcome in a large swine inhalation model of acute, severe H2 S toxicity.