Diabetes mellitus and neuropathy following Vacor ingestion in man

Two patients ingested Vacor, a rodenticide containing the active ingredient N-3 pyridylmethyl-N'-p-nitrophenyl urea. Both patients developed ketosis-prone diabetes mellitus and severe autonomic neuropathy. Niacinamide therapy given nine hours after Vacor ingestion in one patient and 14 hours after ingestion in the other was not successful in preventing these sequelae. Physicians need to be aware of the toxicity of Vacor, and the potential therapeutic benefit of early niacinamide therapy.