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Antizol: Full Drug Profile

Medically reviewed by Min Clinic Staff | Updated: January 2026

Antizol - General Information

Antizol is used as an antidote in confirmed or suspected methanol or ethylene glycol poisoning. Antizol is a competitive inhibitor of alcohol dehydrogenase, the enzyme that catalyzes the initial steps in the metabolism of ethylene glycol and methanol to their toxic metabolites.

 

Pharmacology of Antizol

Antizol is a competitive inhibitor of alcohol dehydrogenase, the enzyme that catalyzes the initial steps in the metabolism of ethylene glycol and methanol to their toxic metabolites. Ethylene glycol is first metabolized to glycoaldehyde which then undergoes further oxidation to glycolate, glyoxylate, and oxalate. It is glycolate and oxalate that are primarily responsible for the metabolic acidosis and renal damage that are seen in ethylene glycol poisoning. {01}{03} Methanol is first metabolized to formaldehyde and then undergoes subsequent oxidation via formaldehyde dehydrogenase to become formic acid. It is formic acid that is primarily responsible for the metabolic acidosis and visual disturbances that are associated with methanol poisoning.

 

Antizol for patients

 

Antizol Interactions

Oral doses of Antizol (10-20 mg/kg), via alcohol dehydrogenase inhibition, significantly reduced the rate of elimination of ethanol (by approximately 40%) given to healthy volunteers in moderate doses. Similarly, ethanol decreased the rate of elimination of Antizol (by approximately 50%) by the same mechanism.

Reciprocal interactions may occur with concomitant use of Antizol and drugs that increase or inhibit the cytochrome P450 system (e.g., phenytoin, carbamazepine, cimetidine, ketoconazole), though this has not been studied.

 

Antizol Contraindications

Antizol should not be administered to patients with a documented serious hypersensitivity reaction to Antizol or other pyrazoles.

 

Additional information about Antizol

Antizol Indication

Antizol is indicated as an antidote for ethylene glycol (such as antifreeze) or methanol poisoning, or for use in suspected ethylene glycol or methanol ingestion, either alone or in combination with hemodialysis

Mechanism Of Action
Antizol (fomepizole) is a competitive inhibitor of alcohol dehydrogenase. Alcohol dehydrogenase catalyzes the oxidation of ethanol to acetaldehyde. Alcohol dehydrogenase also catalyzes the initial steps in the metabolism of ethylene glycol and methanol to their toxic metabolites.
Generic Name
Fomepizole
Synonyms
4-methylpyrazole; Fomepizol [INN-Spanish]; Fomepizole [USAN-INN]; Fomepizolum [INN-Latin]
Drug Category
Antidotes
Drug Type
Small Molecule; Approved
Other Brand Names containing Fomepizole
Antizol;
Absorption
Rapid and complete
Toxicity (Overdose)
Headache, nausea, dizziness
Biotransformation
Primarily hepaticm the primary metabolite is 4-carboxypyrazole (approximately 80 to 85% of an administered dose). Other metabolites include 4-hydroxymethylpyrazole and the N -glucuronide conjugates of 4-carboxypyrazole and 4-hydroxymethylpyrazole.
Half Life
The plasma half-life of Antizol varies with dose, even in patients with normal renal function, and has not been calculated.
Dosage Forms of Antizol
Liquid Intravenous
Chemical IUPAC Name
4-methyl-1H-pyrazole
Chemical Formula
C4H6N2
Organisms Affected
Humans and other mammals