Toxic Alcohols

• Ethanol
• Isopropyl alcohol
• Methanol
• Ethylene glycol

Ethylene glycol toxicity

Methanol Poisoning

Methanol can be found in wood solvent, sterno, paint thinner, photocopier fluid, and cleaning solutions such as windshield wiper fluid and de-icing solutions

Methanol poisoning causes both the effects associated with alcohol (intoxication, nausea etc) and also specific visual problems, including blindness. Eye manifestations can happen as early as 15-20 hours post ingestion. These effects are thought to be secondary to the accumulation of formic acid/formaldehyde. The actual pathophysiology of methanol-associated visual loss is not fully understood but it is thought to be caused by a form of optic neuropathy

Initial Dx -

Clinical History; check retinal inflammation

Management

• fomepizole (competitive inhibitor of alcohol dehydrogenase) or ethanol
• haemodialysis is recommended in addition if any of the following:
  • methanol level ≥50 mg/dL
  • severe metabolic acidosis
  • visual symptoms / end-organ toxicity
  • renal failure
• cofactor therapy with folinic acid to reduce ophthalmological complications

fomepizole, an inhibitor of alcohol dehydrogenase, is now used first-line in preference to ethanol, however it cannot remove toxic substance formed already.

It also prolongs the half-life of ethanol; therefore, simultaneous use with ethanol is not recommended.