activated charcoal and poisoning

Activated charcoal is used in the emergency treatment of certain kinds of poisoning. It helps prevent the poison from being absorbed from the stomach into the body. Sometimes, several doses of activated charcoal are needed to treat severe poisoning. Ordinarily, this medicine is not effective and should not be used in poisoning if corrosive agents such as alkalis (lye) and strong acids, iron, boric acid, lithium, petroleum products (e.g., cleaning fluid, coal oil, fuel oil, gasoline, kerosene, paint thinner), or alcohols have been swallowed, since it will not prevent these poisons from being absorbed into the body.

https://www.mayoclinic.org/drugs-supplements/charcoal-activated-oral-route/description/drg-20070087

For decades, activated charcoal has been used as a 'universal antidote' for the majority of poisons because of its ability to prevent the absorption of most toxic agents from the gastrointestinal tract and enhance the elimination of some agents already absorbed...AC could be considered for patients with an intact airway who present soon after ingestion of a toxic or life-threatening dose of an adsorbable toxin.

https://www.ncbi.nlm.nih.gov/pubmed/17496769