Activated charcoal

Background

• Created from carbonaceous materials
  • Pryolysis (heating to 600-900 degrees C in the absence of oxygen

Mechanism of action

• Large surface area of the charcoal binds toxins and prevents their absorption

Indications

• Ingested drug is adsorbed by charcoal AND one of the following:

1. Time since ingestion is less than 1-2hr
2. Drug has significant enterohepatic circulation
3. Drug delays gastric emptying AND time since ingestion is <4hr
4. Drug is a controlled release preparation AND time since ingestion is <12-18hr

AACT recommendations

• Does NOT recommend routine charcoal administration to all overdose patients
• Consider if patient presents within one hour of an ingestion of a toxic amount of a substance known to be absorbed by charcoal
  • Administration of charcoal after an hour may continue to be beneficial
• They emphasize that there is no definitive data that activated charcoal improves clinical outcome

Contraindications

• Depressed mental status
• Intestinal obstruction
• Increased risk of aspiration (eg. Hydrocarbon ingestion)
• Ingestion of substances not absorbed by charcoal
• Instances where urgent endoscopy will be needed (eg. Ingestion of caustic material)

Limitations

• Does not work with:
  • Heavy metals (Iron, Lead, Arsenic, Mercury, Zinc)
  • Inorganic ions (Lithium, Potassium, Sodium, Flouride and Iodine)
  • Hydrocarbons/essential oils
  • Toxic alcohols (Ethylene Glycol, Methanol, Isopropanol)
  • Acids/bases

Dose

1. 1gm/kg PO
2. Mix with water or juice

Administration

• PO (at least 50 g of charcoal within 20min)
  • It is NOT necessary for charcoal to be administered by a NGT or OGT
  • Improved taste if activated charcoal is chilled
  • In children, may mix with juice, yogurt or ice-cream

Complications

• Aspiration
• Bowel obstruction

See Also

• Gastric Lavage
• Multidose Activated Charcoal (MDAC)

References

• Haddad and Winchester's Clinical Management of Poisoning and Overdose
• Uptodate