Dimethylformamide metabolism following self-harm using a veterinary euthanasia product.

Area of Science:

• Veterinary toxicology
• Clinical pharmacology
• Drug safety evaluation

Background:

• T-61, a veterinary euthanasia drug, contains embutramide, mebezonium, tetracaine, and dimethylformamide (DMF).
• Self-poisoning with T-61 can lead to severe toxicity, with delayed hepatotoxicity potentially linked to DMF.
• The efficacy of N-acetylcysteine (NAC) in mitigating T-61 toxicity is not well-established.

Observation:

• Two male veterinarians self-poisoned with T-61 via injection and ingestion.
• Both patients received N-acetylcysteine (NAC) treatment for varying durations.
• Urine samples were analyzed for dimethylformamide (DMF) and its metabolites, N-methylformamide (NMF) and N-acetyl-S-(N-methylcarbamoyl)cysteine (AMCC).

Findings:

• Both individuals experienced only mild liver injury despite T-61 exposure.
• Rapid urinary excretion of N-methylformamide (NMF) was observed, followed by slower excretion of AMCC.
• Dimethylformamide (DMF) and its metabolite elimination kinetics were slightly prolonged compared to occupational exposure data.

Implications:

• N-acetylcysteine (NAC) administration did not demonstrate a clear effect on the excretion of dimethylformamide (DMF) metabolites (NMF and AMCC).
• Favorable outcomes in these cases suggest T-61 toxicity may be manageable, but the role of NAC requires further investigation.
• Additional studies are warranted to elucidate the impact of NAC on DMF metabolite excretion kinetics and overall toxicity.