activated charcoal
antidote· Brands: Actidose, Charcodote, Carbonix, Liqui-Char, SuperCharPO
Mechanism of action
Activated charcoal adsorbs drugs and toxins onto its large surface area within the gastrointestinal tract, reducing their absorption into the bloodstream. It is not absorbed systemically and acts locally.
Pharmacokinetics
Activated charcoal is not absorbed systemically and remains within the gastrointestinal tract. It is excreted in faeces. The efficacy depends on the time elapsed since toxin ingestion and the type of substance.
Indications & dosing
Single-dose activated charcoal for acute poisoning
Administer as aqueous slurry. Consider local formulary.
- adult · PO: 50 g Single dose · Administer as aqueous slurry. Consider local formulary.
Single-dose activated charcoal for acute poisoning in children
Maximum 50 g.
- pediatric · PO: 1 g/kg Single dose · Maximum 50 g.
Multiple-dose activated charcoal for enhanced elimination (e.g. theophylline, carbamazepine, phenobarbital)
Only for toxins with enterohepatic or entero-enteric circulation. Consider specialist advice.
- adult · PO: 25–50 g q4-6h · Only for toxins with enterohepatic or entero-enteric circulation. Consider specialist advice.
Contraindications & precautions
- Bowel obstruction or ileus · Charcoal cannot pass through and may worsen obstruction
- Gastrointestinal perforation · Risk of leakage into peritoneal cavity
- Unprotected airway with risk of aspiration · Activated charcoal can cause vomiting and aspiration; consider intubation
- Ingestion of non-adsorbable toxins (e.g., alcohols, caustics, hydrocarbons, iron, lithium) · No benefit; may cause harm, e.g., aspiration or perforation
- Administer with caution in patients with reduced level of consciousness; consider intubation to protect the airway.
- Use with caution in pregnancy, children, and elderly; monitor for adverse effects.
- Ensure adequate hydration to prevent constipation; consider a cathartic if required.
- Monitor bowel sounds; discontinue if obstruction or ileus develops.
- Separate administration from other oral medications to prevent reduced absorption.
- Avoid in patients with an underlying condition that predisposes to gastrointestinal perforation.
Adverse effects
- Black stools
- Constipation
- Nausea
- Vomiting
- Aspiration pneumoniaserious
- Bowel obstructionserious
- Intestinal perforationserious
Monitoring, pregnancy & toxicity
- Bowel function (constipation, ileus) · During and after treatment
- Vomiting and risk of aspiration · After administration
- Abdominal distension or pain (possible obstruction) · If multiple doses are given
- Clinical response (toxin levels, symptoms) · As clinically indicated
- Pregnancy: Activated charcoal is not systemically absorbed and is considered safe in pregnancy. Use as indicated for poisoning. Caution is needed due to risk of vomiting and aspiration.
Clinical notes
Activated charcoal is used for poisoning with certain substances. It should be given as soon as possible, preferably within an hour of ingestion. It is ineffective for alcohols, corrosive agents, iron, lithium, and hydrocarbons. Multiple doses may be given for some toxins. Seek specialist advice.
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BNF; local formulary