Fomepizoles

Fomepizole is a medication used to treat poisoning by methanol and ethylene glycol. It works by inhibiting the enzyme alcohol dehydrogenase, which is responsible for metabolizing these toxic alcohols into more harmful substances. Methanol poisoning can cause blindness and death, while ethylene glycol poisoning can lead to kidney failure and other organ damage. Fomepizole is administered intravenously and is considered the antidote of choice for these poisonings.

The drug is a competitive inhibitor of alcohol dehydrogenase. In the body, methanol is metabolized to formaldehyde and then formic acid, and ethylene glycol is metabolized to glycolaldehyde and then glycolic acid. These metabolites are highly toxic. By blocking the initial step of metabolism, fomepizole prevents the formation of these dangerous byproducts, allowing the toxic alcohols to be excreted from the body unchanged.

Fomepizole is typically given as a loading dose followed by repeated doses over a period of time. The exact dosage and duration of treatment depend on the severity of the poisoning and the patient's response. Hemodialysis may also be used in conjunction with fomepizole to help remove the toxic alcohols from the blood. The effectiveness of fomepizole is highest when administered soon after exposure to the toxic alcohol. Side effects are generally mild and can include headache, nausea, and dizziness.