Haemodialysis in Methanol Poisoning
Definition
The most efficient treatment for removing both methanol and formate from circulation and correcting severe metabolic acidosis. The EXTRIP workgroup (US) and European ESICM consensus specify haemodialysis when blood methanol exceeds 50 mg/100 mL or when severe acidosis (pH below 7.25) is present, regardless of symptom severity.
- Indication
- Blood methanol above 50 mg/100 mL or pH below 7.25
- Removes
- Both methanol and its toxic metabolite formate
- Guidance bodies
- EXTRIP workgroup (international), ESICM consensus (Europe)
- Adjunct therapy
- Given alongside fomepizole or ethanol antidote
Common questions
Why is haemodialysis preferred over antidote therapy alone in severe methanol poisoning?+
Fomepizole or ethanol blocks further formate formation but cannot remove methanol or formate already in the blood, so severe cases combine an antidote with haemodialysis to clear the toxic load and reverse the acidosis directly.
What clinical sign most strongly indicates dialysis is needed regardless of symptoms?+
Severe metabolic acidosis with blood pH below 7.25 is treated as an independent trigger, because acidosis severity tracks formate accumulation even when the methanol level or symptom picture looks less alarming.
Does dialysis remove formate as effectively as methanol?+
Yes, both molecules are small and water soluble, so they cross the dialysis membrane readily, which is why haemodialysis is considered efficient here compared with many other poisonings.
Related terms
- Alcohol Dehydrogenase (ADH)
- The hepatic enzyme (isoforms ADH1A, ADH1B, ADH1C) that catalyses the first oxidation step of both ethanol (to acetaldehyde) and methanol (to formaldehyde)...
- Anion-Gap Metabolic Acidosis
- The metabolic acid-base disorder produced by accumulating formate in methanol poisoning. The anion gap (Na+ - [Cl- + HCO3-], normal 8-12 mEq/L)...
- Congener Fingerprinting
- The use of the full volatile congener profile (fusel alcohols, acetaldehyde, ethyl acetate, pyridine, MIBK) in illicit liquor samples to establish batch...
- Fomepizole (4-Methylpyrazole)
- A specific competitive inhibitor of alcohol dehydrogenase (Ki approximately 0.1 µM), used as the preferred antidote for methanol poisoning in high-resource settings....
- Formate (Formic Acid)
- The terminal toxic metabolite of methanol oxidation (HCOO-, pKa 3.7). Formate inhibits cytochrome c oxidase (mitochondrial complex IV), causing optic nerve and...
- FSSAI Methanol Limit
- Under India's Food Safety and Standards (Alcoholic Beverages) Regulations 2018, the maximum methanol content permitted in legally produced and sold spirits is...
- Latency Period
- The 12-24 hour window between methanol ingestion and onset of severe symptoms (visual disturbance, metabolic acidosis), during which the patient may appear...
- Pyridine
- An aromatic nitrogen heterocycle used as a secondary denaturant in Indian denatured spirit formulations (at 1-2% v/v). Its presence in a headspace...
- Vitreous Humour
- The gel-filled interior of the eye, anatomically isolated from hepatic and gastric post-mortem redistribution sources. In forensic toxicology of hooch deaths, vitreous...