An antidote is a drug used to:

An antidote is specifically defined as a substance that counteracts the effects of a poison or toxicity. In medical practice, if a person is exposed to a toxic substance, the use of an antidote can neutralize the toxicity or mitigate its harmful effects. This is particularly vital in emergency situations where rapid intervention is necessary to prevent serious harm or death.

The role of an antidote is to reduce the severity of toxic symptoms or to reverse the toxic effects of certain poisons or overdoses. For example, Naloxone is an antidote used to reverse opioid overdoses, while activated charcoal can absorb many types of toxins from the gastrointestinal tract.

In contrast, enhancing drug effects, accelerating metabolism, or increasing drug absorption are not functions associated with antidotes, as they either promote drug activity or modify the pharmacokinetics of drugs rather than addressing toxicity directly. Therefore, the defining characteristic of an antidote is its ability to counteract toxic effects, affirming that the correct answer is focused on its critical purpose in toxicology and emergency medicine.