Intramuscular cobinamide as an antidote to methyl mercaptan poisoning. (2nd January 2021)

• Record Type: Journal Article
• Authors: Hendry-Hofer, Tara B.; Ng, Patrick C.; McGrath, Alison M.; Soules, Kirsten; Mukai, David S.; Chan, Adriano; Maddry, Joseph K.; White, Carl W.; Lee, Jangwoen; Mahon, Sari B.; Brenner, Matthew; Boss, Gerry R.; Bebarta, Vikhyat S.
• Is Part Of: Inhalation toxicology. Volume 33:Number 1(2021)
• Page Start: 25
• Page End: 32
• Publication Date: 2021-01-02
• Subjects: Methyl mercaptan -- methanethiol -- cobinamide -- inhalation -- swine; Pulmonary toxicology -- Animal models -- Periodicals; Pulmonary toxicology -- Periodicals; Air -- Pollution -- Health aspects -- Periodicals; 616.200471
• DOI: 10.1080/08958378.2020.1866123
• Languages: English
• ISSNs: 0895-8378

Abstract

Abstract: Background: Methyl mercaptan occurs naturally in the environment and is found in a variety of occupational settings, including the oil, paper, plastics, and pesticides industries. It is a toxic gas and deaths from methyl mercaptan exposure have occurred. The Department of Homeland Security considers it a high threat chemical agent that could be used by terrorists. Unfortunately, no specific treatment exists for methyl mercaptan poisoning. Methods: We conducted a randomized trial in 12 swine comparing no treatment to intramuscular injection of the vitamin B12 analog cobinamide (2.0 mL, 12.5 mg/kg) following acute inhalation of methyl mercaptan gas. Physiological and laboratory parameters were similar in the control and cobinamide-treated groups at baseline and at the time of treatment. Results: All six cobinamide-treated animals survived, whereas only one of six control animals lived (17% survival) (p = 0.0043). The cobinamide-treated animals returned to a normal breathing pattern by 3.8 ± 1.1 min after treatment (mean ± SD), while all but one animal in the control group had intermittent gasping, never regaining a normal breathing pattern. Blood pressure and arterial oxygen saturation returned to baseline values within 15 minutes of cobinamide-treatment. Plasma lactate concentration increased progressively until death (10.93 ± 6.02 mmol [mean ± SD]) in control animals, and decreased toward baseline (3.79 ± 2.93 mmol [mean ± SD]) by the end of the experiment in cobinamide-treated animals. Conclusion: We conclude that intramuscular administration of cobinamide improves survival and clinical outcomes in a large animal model of acute, high dose methyl mercaptan poisoning.