When and how to use activated charcoal - Veterinary Medicine
Medicine Center
DVM Veterinary Medicine Featuring Information from:


When and how to use activated charcoal
Learn when decontamination with activated charcoal will benefit your patients and how to best administer it.


When to add a cathartic

Cathartics increase the speed and transit time of material in the GI tract, thus promoting fecal excretion of the toxin. More importantly, cathartics decrease the time available for systemic toxin absorption in the GI tract.

Cathartics typically given to animals are osmotic cathartics: saccharide (e.g. sorbitol) or saline (e.g. sodium sulfate, magnesium citrate, magnesium sulfate) cathartics.1 Sorbitol, which has a sweet taste, is the most commonly given cathartic. Mineral oil is no longer recommended as a cathartic because of the high risk of secondary aspiration.1

Evidence for efficacy

No published clinical studies have investigated the use of a cathartic (with or without activated charcoal) in reducing the bioavailability of drugs or in improving the clinical outcome of poisoned human patients.2 Unfortunately, there is also limited literature evaluating cathartic administration in veterinary medicine, and there are no prospective studies evaluating its use in poisoned patients.


Although cathartics are no longer recommended for use in people,2 in veterinary medicine, one dose of a cathartic with the first dose of activated charcoal is likely appropriate as it may help accelerate GI transit time, lessening the potential of toxicant and activated charcoal desorption.

Many sources of activated charcoal already have sorbitol mixed in and generally can be used as directed on the label (e.g. ToxiBan with sorbitol—Vet-a-Mix; 10 to 20 ml/kg orally). Multidose activated charcoal should not contain cathartics.1,3 If a combination product is not available for the first dose, sorbitol is available as a lone ingredient and can either be mixed with the activated charcoal or given separately immediately after activated charcoal administration or within 60 minutes of toxicant ingestion (70% solution—1 to 2 ml/kg orally).1,3

Adverse effects and contraindications

Adverse side effects of cathartic administration include vomiting, abdominal cramping or pain, diarrhea, dehydration, secondary hypernatremia, and possible hypotension. Serious adverse effects can occur if multiple doses of cathartics are given, in particular dehydration and electrolyte abnormalities, including hypernatremia and hypermagnesemia when using a sodium- or magnesium-containing cathartic.2

Administering cathartics in patients that are dehydrated or fasted, have severe vomiting and diarrhea, or have preexisting renal disease is contraindicated.3 Most of the contraindications for cathartic administration are similar to those for activated charcoal administration.1,3


1. 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.

2. American Academy of Clinical Toxicology and European Association of Poisons Centres and Clinical Toxicologists. Position paper: cathartics. Clin Tox 2004;42(3):243-253.

3. Lee JA. Complications and controversies of decontamination: activated charcoal—to use or not to use, in Proceedings. Am Coll Vet Intern Med Conf, 2010.


Click here