Some of the most common complications resulting from the administration of activated charcoal are vomiting, hypernatremia,
and aspiration pneumonia. The concurrent administration of a parenteral antiemetic (e.g. maropitant 1 mg/kg subcutaneously once a day; ondansetron 0.1 to 0.3 mg/kg intravenously b.i.d. to q.i.d.) should be considered
because of the high prevalence of vomiting from the activated charcoal or cathartic administration or from an emetic previously
used to decontaminate the patient.5 This will also allow more rapid return to oral water or prevention of ongoing losses, mitigating potential rare risks for
Photo courtesy of Garret Pachtinger, VMD, DACVECC
Patients receiving activated charcoal with or without a cathartic should be monitored for rare adverse effects. Clinical signs
of hypernatremia are similar to those of certain toxicoses (e.g. theobromine, caffeine toxicosis)6,7 and include ataxia, decreased or altered mentation, tremors, panting, seizures, or coma. Patients demonstrating these clinical
signs, receiving multiple doses of activated charcoal, or potentially predisposed to these adverse effects (e.g. patients that are dehydrated, that have hyperosmolar syndrome, or that have conditions with increased free water loss) should
have blood work performed (e.g. venous blood gas measurement, electrolyte panel) as needed to monitor their sodium concentrations.2,5
The use of activated charcoal in the decontamination of a poisoned animal continues to have an important role. However, veterinarians
should be aware of the appropriate indications, specific dosing, contraindications, and rare adverse effects seen with the
administration of activated charcoal and cathartics. Before beginning activated charcoal administration, it is always important
to determine that the overall benefit of decontamination outweighs the risks.
Justine A. Lee, DVM, DACVECC, DABT
Sherry Welch, DVM, DABT, DABVT
Pet Poison Helpline, a division of SafetyCall International, PLLC
3600 American Blvd. West, Suite 725
Bloomington, MN 55431
1. American Academy of Clinical Toxicology and European Association of Poisons Centres and Clinical Toxicologists. Position paper:
cathartics. Clin Tox 2004;42(3):243-253.
2. Lee JA. Complications and controversies of decontamination: activated charcoal—to use or not to use, in Proceedings. Am Coll Vet Intern Med Conf, 2010.
3. Howland MA. Antidotes in depth: activated charcoal. In: Flomenbaum N, Goldfrank LR, Hoffman, et al., eds. Goldfrank's toxicologic emergencies. 8th ed. New York: MacGraw-Hill, 2006;128.
4. Schildt J, Jutkowitz LA, Beal MW, et al. Effect of activated charcoal alone versus emesis and activated charcoal on carprofen
absorption following experimental overdose in dogs (abstract presentation). Intern Vet Emerg Crit Care Soc Conf, 2009.
5. Lee JA. Decontamination and detoxification of the poisoned patient. In: Osweiler GD, Hovda LR, Brutlag AG, et al., eds. Five-minute veterinary consult clinical companion: small animal toxicology. 1st ed. Ames, Iowa: Wiley-Blackwell, 2011;5-19.
6. Gazda-Smith E, Synhavsky A. Hypernatremia following treatment of theophylline toxicity with activated charcoal and sorbitol.
Arch Intern Med 1990;150(3):689,692.
7. Moore CM. Hypernatremia after the use of an activated charcoal-sorbitol suspension. J Pediatr 1988;112(2):333.