Fomepizole 2533673 197233668 2008-03-10T14:24:29Z VolkovBot 3035831 robot Adding: [[de:Fomepizol]] {{Chembox new | Name = Fomepizole | IUPACName = | ImageFile = Fomepizole.svg <!-- | ImageSize = 100px --> | ImageName = Chemical structure of Fomepizole | Section1 = {{Chembox Identifiers | CASNo = 7554-65-6 | SMILES = CC1C=NNCC1 }} | Section2 = {{Chembox Properties | Formula = C<sub>4</sub>H<sub>6</sub>N<sub>2</sub> | MolarMass = 82.10 g/mol | BoilingPt = 99-100 °C | Density = 0.99 g/cm<sup>3</sup> }} | Section7 = {{Chembox Hazards | FlashPt = 96.0 °C<}} }} '''Fomepizole''' or '''4-methylpyrazole''' is indicated for use as an [[antidote]] in confirmed or suspected [[methanol]] or [[ethylene glycol]] poisoning. It may be used alone or in combination with [[hemodialysis]]. {03} ==Uses== Fomepizole 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 glycolaldehyde 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. 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. ==Dosage== 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 and therefore has not been calculated. ==Transformation and elimination== [[Hepatic]]; the primary metabolite is 4-carboxypyrazole (approximately 80 to 85% of an administered dose). Other metabolites include the [[pyrazoles]] 4-hydroxymethylpyrazole and the N -glucuronide conjugates of 4-carboxypyrazole and 4-hydroxymethylpyrazole. Following multiple doses, fomepizole rapidly induces its own metabolism via the cytochrome P450 mixed-function oxidase system. In healthy volunteers, 1 to 3.5% of an administered dose was excreted unchanged in the urine. The metabolites also are excreted unchanged in the urine. Fomepizole is [[dialysis|dialyzable]]. ==See also== *[[Ethylene glycol]] *[[Methanol]] ==References== International Programme on Chemical Saftey (IPCS): Methanol (PIM 335), [[http://www.inchem.org/documents/pims/chemical/pim335.htm#10.%20MANAGEMENT]], retreived on March 1, 2008 ==External links== *[http://www.drugs.com/MMX/Fomepizole.html Advanced Consumer Drug Information] *[http://pediatrics.aappublications.org/cgi/content/full/107/1/170 Pediatrics Journal] Vol. 107 No. 1 January 2001, pp. 170 - Fomepizole in the Treatment of Poisoning {{Antidotes}} [[Category:antidotes]] [[Category:pyrazoles]] [[de:Fomepizol]]