What is the dose of activated charcoal by weight?

• A. 0.5 g/kg
• B. 2 g/kg
• C. 1 g/kg
• D. 0.1 g/kg

Answer: (C)

Activated charcoal binds many ingested toxins in the gut, reducing absorption, so the dosing is based on body weight. The standard dose is 1 g per kilogram of body weight, typically with a maximum of about 50 g for adults. This amount provides enough surface area to adsorb toxins without adding unnecessary bulk or raising the risk of vomiting and aspiration. Dosing less than this (0.5 g/kg or 0.1 g/kg) may not bind enough toxin, while a much higher dose (2 g/kg) doesn’t offer extra benefit and increases adverse effects. Activated charcoal is most effective when given within about an hour of ingestion and isn’t useful for certain substances such as alcohols, hydrocarbons, or caustics.