Activated charcoal products are used as universal antidotes in human and animal poisoning. The mechanism of action is irreversible binding of a toxin to the carbon molecules within the activated charcoal. The binding, or adsorption, prevents the toxin from being absorbed in the gastrointestinal tract. For toxins that undergo enterohepatic recirculation, repeated dosing of activated charcoal can reduce systemic absorption. Not all toxins can be adsorbed by activated charcoal. Liquids, sugar alcohols, inhalants and several toxin with unknown mechanisms may not be amenable to treatment with charcoal. Lipid-soluble toxins are more readily adsorbed than water-soluble compounds.
A common additive to activated charcoal solutions is an osmotic cathartic called sorbitol. A cathartic induces fluid movement into the GI tract and encourages more rapid passage of fluid/ingesta through the GI tract. Inappropriate or repeated dosing of sorbitol and other cathartics can lead to diarrhea and dehydration.
Due to recent manufacturer backorders, you may see any of three products on the shelves. Please read the labels carefully to correctly identify whether or not the product contains sorbitol.
- Toxiban without sorbitol is available. Toxiban with sorbitol is on long-term backorder
- UAA gel is available with and without sorbitol
- Actidose (with sorbitol) and Actidose Aqua (without sorbitol) may soon be available
The dose of activated charcoal is 1-5 g/kg, with the most commonly administered dose of 2 g/kg.
- For appropriate toxins: 1st dose of a charcoal product with sorbitol at 10 ml/kg.
- If repeated dosing is recommended, all subsequent doses should be a product without sorbitol at 5- 10 ml/kg. Actidose products should always be dosed at 10 ml/kg
- If repeated doing is recommended, consider admission to hospital for IV fluid administration to help prevent dehydration and associated side effects.
Risks of administration
- Aspiration pneumonitis
- Dehydration (especially with sorbitol-containing products)
- Hypernatremia secondary to intestinal fluid losses
- Potential exacerbation of neurologic manifestations of bromethalin toxicosis due to hypermagnesemia
- Dark stool (not pathologic)
Toxins that do NOT respond to activated charcoal
- Caustic alkalis
- Ferrous sulfate
- Petroleum products