2-4-2021 How does Diethylene Glycol differ from Ethylene Glycol?

Diethylene glycol (DEG), frequently found in the garage, is clearly labeled harmful if swallowed.  It is found in brake fluid, antifreeze, lubricants, wallpaper strippers, mold release agents, inks, and multiple other products.

Most of the documented cases of poisoning have been epidemics where DEG was substituted in pharmaceutical preparations for more expensive, but nontoxic glycols.  In 1937, DEG was used as the solvent in an elixir of sulphanilamide.  In the US, 353 patients received the product-105 people died.

DEG is metabolized in the liver. It is oxidized by alcohol dehydrogenase (ADH) and then enzymatically metabolized to 2-hydroxyethoxyacetic acid (HEAA).  It is not metabolized to ethylene glycol.  The metabolites (probably HEAA) are responsible for the renal (ARF) and neurologic toxicity. 

Clinically, initial symptoms are GI and inebriation. These symptoms may be delayed as long as 48 hours.   Metabolic acidosis develops, and hepatic and renal injury follow.  The final stage is neurological effects, such as neuropathies. 

Diagnosis is difficult and usually made on the history and the presence of an osmolar gap (if early enough after ingestion).  Remember as DEG is metabolized the osmolar gap will become normal.  Similar to ethylene glycol, acid metabolites (organic acid anions) decrease bicarbonate.  Anion gaps may be large.

Treatment is Fomepizole.  Like ethylene glycol, DEG is metabolized by ADH and Fomepizole is a competitive inhibitor of ADH, theoretically preventing the formation of toxic metabolites. 

A toxicologist is available 24 hours a day for consult as needed. The poison center can be reached at 1-800-222-1222.

Prepared by: B. Denese Britt, MS, BSN, CSPI

References:

 SDS - NAPA DOT 3 Brake Fluid 2015.doc

Drugwatch.com. Llamas.M. Drug makers warned for potential diethylene glycol toxin contamination. Published April, 20, 2020).

Olsen, K.R. Poisoning & drug overdose.  McGraw-hill. (2006).

Praxis (Bern 1994). Ethylene glycol intoxication. 2018; 107 (20): 1097 – 1106.

PubMed.gov. Schep,L.J. ClinToxicol Diethylene glycol poisoning. (Phila.) 2009 Sep;47(8):840.

Snellings, W.M. Regulatory toxicology and pharmacology. (Volume 87. Supplement 2, 30 June 2017, Pages S1 – S20.)

The most frequent question asked regarding DEG is if it is the same agent as ethylene glycol.  There is much less known about DEG toxicity as noted in the question, most of the poisonings have been mass poisonings.  Although DEG and ethylene glycol are not the same, both are metabolized via alcohol dehydrogenase (ADH) and are treated with fomepizole to block ADH’s conversion to toxic metabolites. ds

I am interested in any questions you would like answered in the Question of the Week.  Please email me with any suggestion at donna.seger@vumc.org.

Donna Seger, MD

Executive Director

Tennessee Poison Center

www.tnpoisoncenter.org

Poison Help Hotline: 1-800-222-1222