Multiple-dose activated charcoal for enhanced elimination of poisons

Multiple-dose activated charcoal can increase the clearance of some drugs and toxins by interrupting enterohepatic circulation, or by gastrointestinal dialysis (ie drawing already absorbed drugs or toxins back into the gastrointestinal tract down a concentration gradient). It is recommended for enhancing elimination in some drug poisonings, including:

• barbiturates (eg phenobarbital [phenobarbitone], primidone)
• carbamazepine
• colchicine
• dapsone
• phenytoin
• theophylline
• warfarin.

Patients must be alert, cooperative and able to protect their airway to drink a dose of activated charcoal, or be intubated and receive activated charcoal via a nasogastric or orogastric tube—confirm correct placement of the nasogastric or orogastric tube beforehand. Vomiting is not a contraindication to giving activated charcoal in potentially lethal poisonings; however, a nasogastric tube may be needed for administration—there is a risk of pulmonary aspiration when inserting a nasogastric tube.

In patients with a depressed conscious state, rapidly deteriorating conscious state or seizures, only administer activated charcoal once the patient has a protected airway (endotracheal intubation) and a correctly placed nasogastric or orogastric tube.

Before each dose of activated charcoal, examine the patient for evidence of ileus, in particular increasing abdominal distension.

If considering multiple-dose activated charcoal for enhanced elimination of a drug or toxin, seek advice from a clinical toxicologist.

If multiple-dose activated charcoal is indicated for adults, the initial dose is that given for gastrointestinal decontamination with activated charcoal. Follow the initial dose with:

If multiple-dose activated charcoal is indicated for children, the initial dose is that given for gastrointestinal decontamination with activated charcoal. Follow the initial dose with: