Activated Charcoal

How it works

Its very large adsorptive surface area binds many drugs and toxins in the gastrointestinal lumen, reducing systemic absorption; repeated doses can also enhance elimination of some drugs by interrupting enterohepatic and enteroenteric recycling.

Prescribing in practice

• It requires a protected airway because of the aspiration risk — avoid in a drowsy or obtunded patient unless the airway is secured by intubation.
• It does not bind metals (such as iron or lithium), alcohols, corrosives or many solvents, so it is ineffective for these poisonings.
• Repeated doses are used for certain poisons; confirm indications and timing with Toxbase/NPIS.

Monitoring

Assess and monitor conscious level and airway protection before and after administration, watch for vomiting and signs of aspiration, and review bowel sounds, especially with repeated doses.

Counselling the patient

• Warn the team that charcoal is only useful early and that a safe, protected airway is a prerequisite.
• Note that it is ineffective against metals, alcohols and corrosives.
• Check Toxbase/NPIS for whether single or repeated doses are appropriate for the specific poison.

Evidence & guidelines

Standard gut decontamination option in selected poisonings (Toxbase/NPIS).