Page 686 - Veterinary Toxicology, Basic and Clinical Principles, 3rd Edition

Alcohols and Glycols Chapter | 49 651

VetBooks.ir FIGURE 49.2 Pathways of formation of
toxic metabolites for propylene glycol and
ethylene glycol.

Mechanism of Action developing solutions, hydraulic brake fluid and motor oil,
and inks and wood stains (Davis et al., 1997). The most
Butylene glycol is a CNS depressant much like ethanol,
readily available source of EG in the home is antifreeze
due to the effect of the metabolite gamma-
solutions, which consist of approximately 95% EG.
hydroxybutyrate on the CNS. In large quantities butylene
Because of its sweet taste, EG is often consumed uninten-
glycol can result in seizures and respiratory arrest.
tionally by children and animals. Aversive bittering agents
may be added to EG containing antifreeze to try to prevent
Treatment
ingestions by making the antifreeze unpalatable.
Therapy for butylene glycol toxicosis in humans is The MLDs reported in the literature for humans, rats,
supportive, similar to therapy for ethanol toxicosis. dogs, and cats are 1.57, 3.8 11, 6.7 7.3, and 1 g/kg,
respectively (LaKind et al., 1999). Based on the MLDs, on
a body weight basis, EG appears to be more acutely toxic
Ethylene Glycol Toxicosis
to humans and cats than to other experimental animals.
EG (1,2-ethanediol, HOCH 2 CH 2 OH) is used primarily as
an antifreeze and a windshield deicing agent. It is also used
as a cryoprotectant for embryo preservation, in the manu- Toxicokinetics
facture of polyester compounds, as a solvent in the paint Before it is metabolized, EG is no more toxic than etha-
and plastic industries, and as an ingredient in photographic nol, although EG is a more potent CNS depressant than