Methanol poisoning

T51.1


DESCRIPTION

No longer found in methylated spirits as methanol replaced with less toxic agents 10-20 years ago. Methanol may be found in stove or model fuels, or in antifreeze and windscreen washes. Methanol may result in an ethanol-like inebriation in the early phase.

Presentation:

  • Ingestion of methanol results in initial mild inebriation (headache, confusion, nausea and vomiting) followed by an asymptomatic period.
  • Later, toxic metabolite (formic acid) formation results in severe high anion gap metabolic acidosis, and retinal toxicity (with visual impairment to total blindness).

Anion gap calculation = Na – (CI + HCO3) (Normal = 8-16)

MEDICINE TREATMENT

If acidotic or visual disturbances;

Start with immediate ethanol antidote therapy (See Ethylene glycol poisoning), and evaluate for urgent dialysis, if available.

LoEIII [58]