METHYL ALCOHOL (Methanol) POISONING

Methanol is used as an industrial solvent and is an ingredient of methylated spirits. It is often ingested for self-harm or as a substitute for alcohol. It can form in home-distilled crude alcohol due to incomplete conversion to ethanol.

A dose >1 g/kg is potentially lethal: it is transformed into toxic metabolites and causes profound acidosis.

Clinical features

  • Initial inebriation (as in alcohol assumption)
  • Latent asymptomatic period of 12-24 hours
  • Headache, dizziness, nausea, vomiting, visual disturbances, CNS depression and respiratory failure
  • Toxic metabolites may cause severe acidosis and retinal/ optic nerve damage

Management

  • Gastric aspiration and lavage
    • Only use if done within 2 hours of ingestion (it has a very rapid absorption)
  • Charcoal is NOT USEFUL
  • Give 1.5-2 ml/kg of oral alcohol 40% (e.g. waragi, whisky, brandy) in 180 ml of water as loading dose, oral or via NGT
    • Maintenance dose: 0.3 ml/kg/hour
  • Sodium bicarbonate 50-100 ml IV over 30-45 minutes
  • Check for and correct hypoglycaemia