Q: Fomepizole can be use in methanol or ethylene glycol poisoning, but not in Ethanol poisoning. Why?

Answer:  Fomepizole not only prolongs the half-life of ethanol but allows for greater level of intoxication at lower doses.

Fomepizole slows the production of acetaldehyde by alcohol dehydrogenase and allows more time for acetaldehyde dehydrogenase to detoxify it. Consequently, a patient will have a prolonged and deeper level of intoxication for even at small dosage of ethanol.