Acute Hepatic Failure in a Dog after Xylitol Ingestion.

Xylitol is a five-carbon sugar alcohol produced from natural resources frequently used as a sugar substitute for humans. We report the development and successful treatment of acute hepatic failure and coagulopathy in a dog after xylitol ingestion. A 9-year-old 4.95 kg (10.9 lb) neutered male Chihuahua was evaluated at a veterinary clinic for vomiting after ingesting 224 g (45 g/kg, 20.5 g/lb) of granulated xylitol. Hypoglycemia developed within 1-2 h, elevated liver values, suggesting the development of acute hepatic failure, within 12 h and coagulopathy less than 24 h after ingestion. Treatment included maropitant, intravenous dextrose, phytonadione, metronidazole, and fresh frozen plasma. N-acetylcysteine (NAC) and S-adensoyl-L-methionine (SAMe) provided hepatic detoxification and support. The dog survived and liver values returned to normal within 1 month post ingestion. No adverse effects to hepatic function have been identified 2 years after acute xylitol toxicity. This paper is one of the few reports of successful management of a dog with hypoglycemia, hepatic failure, and coagulopathy caused by xylitol toxicity. To date, this is the highest published xylitol dose survived by a dog, as well as the only reported case that documents laboratory changes throughout the course of toxicity and includes normal hepatic indices for 7 months following xylitol toxicity. The rapidly expanding use of xylitol in a variety of products intended for human consumption has led to a rise in xylitol toxicity cases reported in dogs, and clinicians should be aware that more dogs may potentially be exposed and develop similar manifestations.

Inhibition of polyol formation in rat lens by verapamil.

Accumulation of sorbitol and xylitol in rat lenses incubated in medium-199 with and without verapamil has been studied. This antihypertensive drug, known to attenuate hypertension by its calcium channel blocking effect, is also known to inhibit cataract formation in diabetes. The present studies have demonstrated that verapamil's effect against cataract could also be partially related to its aldose reductase inhibitory activity, in addition to the Ca++ channel blocking activity. The accumulation of sorbitol in the lenses incubated with high glucose in the presence of 400 microM verapamil was only 2.3 mmoles/Kg wet weight against 11.3 mmoles/Kg in its absence. The level of xylitol attained in the presence of 10 mM xylose was 25.7 +/- 2.4 mmoles/Kg. It decreased to 4.8 +/- 1.2 mmoles/Kg in presence of 400 microM verapamil. Hence, verapamil is significantly effective in inhibiting lens aldose reductase dependent polyol synthesis, an action simultaneous with its effect on calcium penetration.