The cure for methanol is in the name

This is something that popped up in my head because of the news recently about those poor tourists in Laos who died from methanol poisoning.^[1] It triggered a memory that ethanol^[2] is actually the bootleg cure for methanol poisoning.

The damaging part of methanol is when your body metabolises it into formic acid.^[3] Formic acid affects mitochondrial function and drops blood pH, causing organ failure.

The cure therefore is to keep your body busy enough metabolising something else until your kidneys and lungs manage to filter out the still-intact methanol. The only readily available substance that allows for this is ethanol,^[4] which is preferentially processed by the alcohol dehydrogenase (ADH) enzyme in our liver.

Turns out you need about one bottle of vodka across roughly two days to flush out half the methanol consumed. Here's the excerpt from ChatGPT:

The amount of ethanol needed depends on the amount of methanol ingested and the individual’s metabolism. Here’s how it works:

Key Pharmacological Details:

• Methanol Metabolism Rate: Methanol is metabolised by alcohol dehydrogenase (ADH) at about 8 mg/kg/hour in humans.
• Ethanol Affinity for ADH: Ethanol needs to saturate ADH to outcompete methanol. Blood ethanol levels of about 100 mg/dL (0.1 g/dL) are typically sufficient.

Dosing Rule of Thumb:

• To block methanol metabolism effectively, you need to maintain a blood ethanol concentration of 100–150 mg/dL.
• This requires 0.1–0.15 grams of ethanol per kilogram of body weight per hour, sustained for as long as methanol is present in the system.

Example Calculation for a 70 kg Person:

• Ethanol Maintenance Dose
  • A standard vodka (40% ethanol) drink contains about 10 g of ethanol per 25 mL shot.
  • This would mean roughly 17.5 mL of vodka per hour.
• Duration
  • Methanol’s half-life without dialysis is ~40 hours (can be longer with ethanol, as metabolism slows). You might need to consume ethanol for 40–60 hours until methanol is excreted or detoxified.

Total ethanol required: Equivalent to 700 mL of vodka.