Name two common contraindications to activated charcoal.

• A. Ingestion of caustics or hydrocarbons
• B. Inability to protect airway/AMS
• C. Ingestion of ethanol
• D. Ingestion of caustics or hydrocarbons; inability to protect airway/AMS

Answer: (D)

Activated charcoal works by adsorbing toxins in the GI tract to limit absorption, but it isn’t used in every poisoning. The two common contraindications are: ingestion of caustics or hydrocarbons, and an inability to protect the airway or an altered mental status. Caustic substances can burn mucosa, and charcoal can complicate assessment or worsen injury; hydrocarbons carry a high risk of aspiration and are not reliably adsorbed, so giving charcoal offers little benefit and can be harmful. If a patient cannot protect the airway or is drowsy or confused, there’s a real danger of aspirating the charcoal, which can cause airway obstruction or chemical pneumonitis, so airway protection is needed first. Ethanol ingestion is not a contraindication, as charcoal can adsorb ethanol in many cases, though each situation depends on timing and clinical context.