The health care practitioner at an emergency care facility knows that activated charcoal is given for drug overdose.
what is the benefit of using this substance?

It reduces the absorption of a poisonous chemical in the small and large intestine.

Explanation:

The charcoal can be used to remove impurities of the environment. This acts as the best skin care to make the skin healthy and free from any harmful pollutants.

The charcoal can be used to reduce the harmful effect of the overdose of the drug. This charcoal might reduce the poison from the body and mainly acts on the large intestine and small intestine of the drug. The excess drug can be easily neutralize by the charcoal.

Thus, the answer is this reduces the absorption of a poisonous chemical in the small and large intestine.