Clinical Information

Ethylene glycol is present in antifreeze products, deicing products, detergents, paints, and cosmetics. Ethylene glycol has initial central nervous system (CNS) effects resembling those of ethanol and may be ingested accidentally or for the purpose of inebriation or suicide. Ethylene glycol itself is relatively nontoxic, however, metabolism of ethylene glycol by alcohol dehydrogenase results in the formation of a number of acid metabolites, including oxalic acid and glycolic acid. These acid metabolites are responsible for much of the toxicity of ethylene glycol.

Clinically, poisoning has historically been divided into three stages, although timing may vary, and stages may overlap. The first stage typically begins 30 minutes to 12 hours after ingestion due to the intoxicating effects of the ethylene glycol and may range from mild CNS depression to coma. The second stage begins 12 to 24 hours after ingestion and is characterized severe metabolic acidosis, due to the accumulation of acid metabolites. The third stage occurs 24 to 72 hours after ingestion and is characterized by renal failure due to calcium oxalate crystal deposition in the proximal tubules.

Ethylene glycol toxicity can be treated with 4-methylpyrazole (4-MP; fomepizole) or ethanol by competitively inhibiting alcohol dehydrogenase and thereby preventing conversion of ethylene glycol to its toxic metabolites.