Fomepizole

Mechanism :

Fomepizole competitively inhibits alcohol dehydrogenase, an enzyme which catalyzes the metabolism of ethanol, ethylene glycol, and methanol to their toxic metabolites.

Indication :

Ethylene glycol or methanol poisoning

Contraindications :

Hypersensitivity to fomepizole, other pyrazoles, or any component of the formulation.

Dosing :

IV:

Loading dose of 15 mg/kg should be administered, followed by doses of 10 mg/kg every 12 hours for 4 doses, then 15 mg/kg every 12 hours thereafter until ethylene glycol or methanol concentrations have been reduced to <20 mg/dL and patient is asymptomatic

Adverse Effect :

Headache, nausea, bradycardia, facial flushing, hypotension, phlebitis, shock, tachycardia, dizziness, drowsiness, metallic taste, agitation, altered sense of smell, anxiety, seizure, speech disturbance, vertigo, unpleasant taste, abdominal pain, decreased appetite, diarrhea, heartburn, hiccups, vomiting, anemia, disseminated intravascular coagulation (DIC), eosinophilia, lymphangitis, increased liver enzymes, application site reaction, inflammation at injection site, pain at injection site.

Interaction :

Ethanol: Decreases the rate of fomepizole elimination by ~50%; conversely, fomepizole decreases the rate of elimination of ethanol by ~40%.

Hepatic Dose :

Fomepizole undergoes hepatic metabolism. No dosage adjustment is recommended.