What is the primary action of activated charcoal?

• A. Absorbs toxic substances from the GI tract
• B. Neutralizes toxins in the bloodstream
• C. Increases intestinal motility
• D. Reduces absorption of vitamins

Answer: (A)

Activated charcoal acts by adsorption of ingested toxins in the gastrointestinal tract. Its porous surface traps substances as they pass through the gut, preventing their absorption into the bloodstream and thereby reducing systemic toxicity. It stays in the GI lumen and is excreted in the stool, so it does not neutralize toxins that are already circulating. It is most effective when given promptly after ingestion (often within about an hour), but not for all poisons. It does not increase intestinal motility, and while it can bind other substances, including some vitamins or medications, that is not its primary purpose and it may interfere with the absorption of some agents if used together.