Antizol Vet

Generic name: fomepizole
Dosage form: FOR ANIMAL USE ONLY

Rx only Pr


Sterile for use in dogs only Dilute 1:19 in sterile 0.9% sodium chloride injection prior to intravenous injection

CAUTION

Federal Law restricts this drug to use by or on the order of a licensed veterinarian.

ACTIVE INGREDIENT

One single use vial (1.5 mL) of Antizol-Vet® (fomepizole) for injection contains 1.5 grams of fomepizole without excipients. When one vial is diluted with 28.5 mL of sterile 0.9% sodium chloride, the final diluted concentration is 50 mg/mL fomepizole.

PHARMACOLOGY

Antizol-Vet® is a synthetic alcohol dehydrogenase inhibitor. It is a 4-methyl-substituted five-membered ring structure with the molecular formula C4H6N2 and a molecular weight of 82.1 grams per mole. The chemical name is 4-methylpyrazole. Antizol-Vet® acts as a competitive inhibitor of the liver enzyme alcohol dehydrogenase. The oxidation of ethylene glycol to glycoaldehyde by alcohol dehydrogenase is a critical step in the metabolism of this compound. Alcohol dehydrogenase is also involved in the metabolism of ethanol, methanol, and other hydrocarbon alcohols. Glycolic, glyoxalic, and oxalic acids, the metabolites of ethylene glycol, are the substances responsible for the severe metabolic acidosis and renal tubular epithelial damage present in poisoned dogs. Once inhibition of alcohol dehydrogenase has been achieved by treatment with Antizol-Vet®, the remaining unchanged ethylene glycol and its metabolites are excreted in the urine.

INDICATIONS

Antizol-Vet® is indicated as an antidote for ethylene glycol (antifreeze) poisoning in dogs that have ingested or are suspected of having ingested ethylene glycol.

PROGNOSIS

Antizol-Vet® is only effective if administered prior to complete metabolism of ethylene glycol. To evaluate whether ethylene glycol has been completely metabolized, it is advisable to measure serum BUN and creatinine, and to monitor urine output. Correction of dehydration is essential to obtain accurate serum BUN and creatinine values. Serum concentrations of blood urea nitrogen >40 mg/dl and creatinine >1.8 mg/dl that do not resolve after dehydration is corrected indicate that ethylene glycol has been fully metabolized and significant renal damage may exist. However, if urine flow is maintained, benefit-to-risk considerations suggest that treatment with Antizol-Vet® is warranted.

Contraindications

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