Antidoten

Antidoten (antidotes) are substances that counteract the effects of poisons or toxins. They act by interfering with the toxic agent, either by neutralizing it, binding it so it cannot act, removing it from the body, or blocking the biological consequences of exposure. Antidotal therapy is a component of clinical toxicology and is typically guided by poison control centers or medical toxicologists. The effectiveness of an antidote depends on the poison, the amount involved, and how quickly treatment begins.

Antidotes are categorized as specific or nonspecific. Specific antidotes act on a particular toxin or its mechanism, such as naloxone for opioid overdose, flumazenil for benzodiazepines, pralidoxime for organophosphates, hydroxocobalamin for cyanide, or the use of vitamin K to counteract warfarin. Other examples include chelating agents for metal poisonings, such as dimercaprol (BAL) and EDTA, and deferoxamine for iron overload. For poisoning from methanol or ethylene glycol, fomepizole is used to inhibit alcohol dehydrogenase, while N-acetylcysteine replenishes glutathione in acetaminophen poisoning. Nonspecific measures, such as activated charcoal, or supportive care, may be employed when no specific antidote exists or as adjuncts in early poisoning.

Antidotes carry risks and are not universally appropriate for every poisoning. Some antidotes may cause harm if misused or if damage from the poison has already occurred. Treatment decisions rely on accurate diagnosis and timing, and they are usually administered in hospital settings under medical supervision or through poison centers.

See also: poison control centers and clinical toxicology.