What is the definition of an antidote in a medical context?

An antidote is specifically defined as a substance that counteracts the effects of a poison or toxin. In a medical context, antidotes are crucial for treating cases of poisoning, as they help to neutralize or inhibit the effects of harmful substances that have been ingested, inhaled, or injected. For instance, in cases of opioid overdose, naloxone is an antidote that rapidly reverses the life-threatening effects of opioids on respiration.

In contrast, the other options describe different categories of substances that do not fit the definition of an antidote. Enhancers of medication, such as adjuncts, work to improve the efficacy of certain treatments but do not serve to counteract toxins. Substances used to treat infections relate to antimicrobial agents, which specifically target pathogens rather than poisons. Finally, treatments for chronic illnesses often involve long-term management strategies and medications that do not specifically negate the effects of poisons. Therefore, the essence of what an antidote represents as a life-saving intervention in intoxication situations makes the chosen answer the most accurate.