Protective effects of fomepizole on 2-chloroethanol toxicity

Hum Exp Toxicol. 2010 Jun;29(6):507-12. doi: 10.1177/0960327109358612. Epub 2010 Jan 7.

Abstract

2-Chloroethanol (2-CE) is a widely used industrial solvent. In Taiwan, Taiwanese farmers apply 2-CE on grape-vines to accelerate grape growth, a practice that in some cases have caused poisoning in humans. Thus, there is strong interest in identifying antidotes to 2-CE. This study examines the protective role in 2-CE intoxicated rats. Alcohol dehydrogenase and glutathione were hypothesized to be important in the metabolism of 2-CE. This study used fomepizole, an alcohol dehydrogenase inhibitor, and chemicals that affected glutathione metabolism to study 2-CE toxicity. Notably, fomepizole 5 mg/kg significantly increased median lethal dose (LD(50)) of 2-CE from 65.1 to 180 mg/kg and reduced the production of a potential toxic metabolite chloroacetaldehyde (CAA) in animal plasma. In contrast, disulfiram (DSF), an aldehyde dehydrogenase inhibitor, increased the toxicity of 2-CE on the lethality in rats. Additional or pretreatment with N-acetylcysteine (NAC) and fomepizole significantly reduced plasma CAA concentrations. Fomepizole also significantly reduced 2-CEinhibited glutathione activity. Otherwise, pretreatment with NAC for 4 days followed by co-treatment with fomepizole significantly decreased formation of the metabolic CAA. These results indicated that its catalytic enzyme might play a vital role during 2-CE intoxication, and the combination of fomepizole and NAC could be a protective role in cases of acute 2-CE intoxication.

MeSH terms

  • Acetaldehyde / analogs & derivatives
  • Acetaldehyde / blood
  • Acetylcysteine / pharmacology
  • Acetylcysteine / therapeutic use
  • Alcohol Dehydrogenase / antagonists & inhibitors*
  • Aldehyde Dehydrogenase / antagonists & inhibitors
  • Animals
  • Antidotes / pharmacology
  • Antidotes / therapeutic use*
  • Antioxidants / pharmacology
  • Antioxidants / therapeutic use
  • Disulfiram / pharmacology
  • Disulfiram / therapeutic use
  • Drug Synergism
  • Enzyme Inhibitors / therapeutic use*
  • Ethylene Chlorohydrin / metabolism
  • Ethylene Chlorohydrin / toxicity*
  • Fomepizole
  • Glutathione / metabolism
  • Kidney / drug effects
  • Kidney / metabolism
  • Lethal Dose 50
  • Liver / drug effects
  • Liver / metabolism
  • Male
  • Pyrazoles / pharmacology
  • Pyrazoles / therapeutic use*
  • Rats
  • Rats, Sprague-Dawley
  • Solvents / metabolism
  • Solvents / toxicity*

Substances

  • Antidotes
  • Antioxidants
  • Enzyme Inhibitors
  • Pyrazoles
  • Solvents
  • Ethylene Chlorohydrin
  • Fomepizole
  • chloroacetaldehyde
  • Alcohol Dehydrogenase
  • Aldehyde Dehydrogenase
  • Glutathione
  • Acetaldehyde
  • Disulfiram
  • Acetylcysteine