The Role of Hemodialysis and Fomepizole in Ethylene Glycol Intoxication

Ethylene glycol is one of the most common toxic alcohol ingestions requiring hemodialysis for treatment. With the FDA approval in 1997 of fomepizole (4-methylpyrazole), the indications for hemodialysis in addition to fomepizole for ethylene glycol poisoning have been examined in recent articles and case reports. Fomepizole, a competitive inhibitor of alcohol dehydrogenase, binds to the same site on the enzyme as ethanol, however the pharmacokinetics of fomepizole are more predictable, and with fewer side effects compared to ethanol. Current guidelines cited in the literature for the use of hemodialysis in ethylene glycol poisoning include patients with severe metabolic acidosis (pH 7.3), serum ethylene glycol level 50 mg/dL, acute kidney injury, and deteriorating vital signs despite intensive care. This article is a review of the current literature with regard to the use of fomepizole as monotherapy for ethylene glycol poisoning, as well as the indications for hemodialysis in ethylene glycol poisoning. *Corresponding author: Gregory K. Buller, Department of Internal Medicine, Saint Mary’s Hospital, Waterbury, Connecticut, USA, E-mail: [email protected] Received March 30, 2012; Accepted May 19, 2012; Published May 21, 2012 Citation: Buller GK, Moskowitz CB, Eckardt K (2012) The Role of Hemodialysis and Fomepizole in Ethylene Glycol Intoxication. J Nephrol Therapeutic S10:004. doi:10.4172/2161-0959.S10-004 Copyright: © 2012 Buller GK, et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Introduction Ethylene glycol is present in many common substances such as antifreeze, de-icing substances, detergents, lacquers, and polishes [1]. Ethylene glycol itself is not toxic; rather the metabolites, glycolic acid and oxalic acid exert their toxic effects. Three stages of toxicity from ethylene glycol are classically identified: 1) CNS stage, 30 min to 12 hours after ingestion with features of altered mental status, ataxia and slurred speech; 2) cardiopulmonary stage, 12-24 hours after ingestion with hypertension, tachycardia, congestive heart failure, and adult respiratory distress syndrome; 3) renal stage, 24-72 hours after ingestion with flank pain, calcium-oxalate crystalluria, and oliguria [1]. Of interesting note, two forms of oxalate crystals can be present in the urine in ethylene glycol poisoning, one more specific than the other. A dumbbell shaped monohydrate crystal is most common, however the dihydrate form is most specific, as the monohydrate form can be present in those who consume large quantities of vitamin C as well as diets high in urate. The dihydrate form also requires a higher concentration of oxalate to be present, and is thus more indicative of ethylene glycol poisoning [2].