An antidote is a drug, chelating substance, or a chemical that counteracts (neutralizes) the effects of another drug or a poison.
There are dozens of different antidotes; however, some may only counteract one particular drug, whereas others (such as charcoal) may help reduce the toxicity of numerous drugs.

Antidotes include etc:

• Acetylcysteine for acetaminophen poisoning
• Activated charcoal for most poisons
• Atropine for organophosphates and carbamates
• Digoxin immune fab for digoxin toxicity
• Dimercaprol for arsenic, gold, or inorganic mercury poisoning
• Flumazenil for benzodiazepine overdose
• Methylene blue for drug-induced methemoglobinemia
• Naloxone for opioid overdose
• Pralidoxime for poisoning by anti-cholinesterase nerve agents.