Vetdrugs 2.0Activated charcoal is a gastrointestinal adsorbent used in veterinary toxicology to reduce absorption of selected ingested poisons. Its porous structure gives it a large binding surface. It acts locally within the digestive tract rather than as a circulating antidote, and its usefulness depends on the particular substance and its gastrointestinal or enterohepatic behavior.
Group
Gastrointestinal adsorbent antidote
Mechanism of Action
Activated charcoal attracts and holds susceptible molecules on its large internal surface through noncovalent physical interactions. This adsorption leaves less free toxin available for absorption across the intestinal mucosa. For selected substances excreted into bile or secreted back into the gut, continued intestinal binding can interrupt enterohepatic or enteroenteric recycling and promote elimination through the feces.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Gastrointestinal decontamination | 1–4 g/kg | PO | Once | Give promptly after ingestion when charcoal is appropriate for the toxin and airway protection is adequate. |
| Gastrointestinal decontamination | 2 g/kg | PO | Once | Common single-dose alternative. |
| Selected recirculating toxin exposure | 1–4 g/kg | PO | Every 4–6 h | Repeat only when the specific toxin warrants multiple-dose charcoal. Only the first dose should contain a cathartic; monitor hydration and sodium. |
| Alternative decontamination dose | 1–5 g/kg | PO | Dilute as a slurry, approximately 1 g charcoal per 5–10 mL water. Use toxin-specific assessment and protect the airway. |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Gastrointestinal decontamination | 1–4 g/kg | PO | Once | Give promptly after ingestion when charcoal is appropriate for the toxin and airway protection is adequate. |
| Selected recirculating toxin exposure | 1–4 g/kg | PO | Every 4–6 h | Repeat only when the specific toxin warrants multiple-dose charcoal. Only the first dose should contain a cathartic; monitor hydration and sodium. |
| Alternative decontamination dose | 1–5 g/kg | PO | Dilute as a slurry, approximately 1 g charcoal per 5–10 mL water. Use toxin-specific assessment and protect the airway. |
Large animals
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Gastrointestinal decontamination | 1 g/kg | PO | Suggested large-animal dose; clinical use is less well reported. |
Ruminants
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Plant intoxication | 1–5 g/kg | PO | Oral slurry, approximately 1 g per 5 mL water; repeated dosing is toxin-specific. |
Horses
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Gastrointestinal decontamination | Reference only | PO | Historical fixed amounts: foals at least 250 g and adults up to 750 g as a slurry in a size-appropriate volume up to 4 L warm water via stomach tube. Open minimum/maximum statements are not invented bounded dose ranges. |
Indications
- Gastrointestinal decontamination after ingestion of a toxin or drug that is adsorbed by activated charcoal in dogs, cats and other veterinary patients.
- Enhancement of elimination of selected toxins with clinically important enterohepatic or enteroenteric recycling, using a toxin-specific multidose treatment approach.
Contraindications
- Do not administer into an unprotected airway or when aspiration risk cannot be controlled.
- Ineffective for mineral acids and caustic alkalis; avoid obscuring lesions when endoscopy is needed.
Interactions
- Adsorbs many concurrently administered oral medicines.
- Separate other oral therapeutic medicines by at least three hours when feasible.
- Dairy products, mineral oil and polyethylene-glycol electrolyte bowel preparations can reduce adsorption.
Adverse effects
- Constipation
- Diarrhea from sorbitol-containing products
- Serious respiratory complications if aspirated
- Hypernatremia, especially in small dogs or cats
- Aspiration pneumonitis
- Black stools
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Activated charcoal suspension 15 g/72 mL Single-active suspension; sorbitol-containing products require separate composition and administration assessment. | Oral Liquid | 15 g / 72 mL | PO |
| Activated charcoal suspension 50 g/240 mL | Oral Liquid | 50 g / 240 mL | PO |
| Activated charcoal 20% slurry 1 g per final 5 mL; not a sorbitol-containing combination. | Oral Liquid | 1 g / 5 mL | PO |
Monitoring and Administration
Assess the toxin and time since ingestion; benefit decreases after about 4 hours for many exposures. Monitor the underlying toxicosis because adsorption is incomplete.
A charcoal-to-toxin ratio greater than 40:1 may be needed; this does not replace toxin-specific assessment. Do not automatically repeat sorbitol-containing products.
Suspension doses of 6–12 mL/kg in dogs and cats and 6–10 mL/kg in large animals are described without assigning an exact concentration; use mass-based dosing with a known product.
Charcoal poorly adsorbs alcohols, lithium, iron salts, petroleum distillates and several small ionic compounds. Do not use it automatically for every toxin.
Monitor serum sodium if neurologic signs occur. Cathartic repetition can cause dehydration and electrolyte loss; do not add one where significant diarrhea already exists.
A 20% slurry made as 1 g charcoal in a final 5 mL contains 0.2 g/mL; 10 mL/kg supplies 2 g/kg, not 10 g/kg.