However, these lower doses may therefore produce less chronic toxicity and provide a harm minimization approach to chronic alcoholism. It is, in essence, the antithesis of a disulfiram approach which tries to increase the buildup of acetaldehyde resulting in positive punishment for the patient. Compliance, and adherence, is a substantial problem in disulfiram-based approaches. Disulfiram also has a considerably longer half-life than that of fomepizole, requiring the person to not drink ethanol in order to avoid severe effects. If the person is not adequately managed on a benzodiazepine, barbiturate, acamprosate, or another GABAA receptor agonist, the alcohol withdrawal syndrome, and its attendant, life-threatening risk of delirium tremens "DT", may occur. Disulfiram treatment should never be initiated until the risk of DT has been evaluated, and mitigated appropriately. Fomepizole treatment may be initiated while the DT de-titration sequence is still being calibrated based upon the persons withdrawal symptoms and psychological health. Adverse effects
Common side effects associated with fomepizole use include headache and nausea. Kinetics
Absorption and distribution
Fomepizole distributes rapidly into total body water. The volume of distribution is between 0.6 and 1.02 L/kg. The therapeutic concentration is from 8.2 to 24.6 mg (100 to 300 micromoles) per liter. Peak concentration following single oral doses of 7 to 50 mg/kg of body weight occurred in 1 to 2 hours. The half-life varies with dose, so has not been calculated. Metabolism and elimination
Hepatic; the primary metabolite is 4-carboxypyrazole (about 80 to 85% of an administered dose).
Fomepizole, also known as 4-methylpyrazole, is a medication used to treat methanol and ethylene glycol poisoning. It may be used alone or together with hemodialysis. It is given by injection into a vein.Common side effects include headache, nausea, sleepiness, and unsteadiness. It is unclear if use during pregnancy is safe for the baby. Fomepizole works by blocking the enzyme that converts methanol and ethylene glycol to their toxic breakdown products.Fomepizole was approved for medical use in the United States in 1997. It is on the World Health Organizations List of Essential Medicines. Medical use
Fomepizole is used to treat ethylene glycol and methanol poisoning. It acts to inhibit the breakdown of these toxins into their active toxic metabolites. Fomepizole is a competitive inhibitor of the enzyme alcohol dehydrogenase, found in the liver. This enzyme plays a key role in the metabolism of ethylene glycol, and of methanol. Ethylene glycol is first metabolized to glycolaldehyde by alcohol dehydrogenase. Glycolaldehyde then undergoes further oxidation to glycolate, glyoxylate, and oxalate. Glycolate and oxalate are the primary toxins responsible for the metabolic acidosis, and for the renal damage, seen in ethylene glycol poisoning. Methanol is first metabolized to formaldehyde by alcohol dehydrogenase. Formaldehyde then undergoes further oxidation, via formaldehyde dehydrogenase, to become formic acid. Formic acid is the primary toxin responsible for the metabolic acidosis, and for the visual disturbances, associated with methanol poisoning.By competitively inhibiting the first enzyme, alcohol dehydrogenase, in the metabolism of ethylene glycol and  methanol, fomepizole slows the production of the toxic metabolites.