What is the antidote for acetaminophen overdose?

• A. Naloxone
• B. Activated charcoal
• C. N-acetylcysteine
• D. Flumazenil

Answer: (C)

N-acetylcysteine is the antidote for acetaminophen overdose. When acetaminophen is taken in excess, a toxic metabolite (NAPQI) forms and depletes the liver’s glutathione stores, leading to liver cell injury. N-acetylcysteine replenishes glutathione and also provides a sulfhydryl group that helps detoxify NAPQI, reducing hepatotoxicity. The sooner NAC is started, the better the protection, with the most benefit when begun within about 8–10 hours of ingestion, though it can still help later. It can be given orally or intravenously, with regimens tailored to the route. Activated charcoal may limit absorption if given very soon after ingestion but does not detoxify the toxin. Other antidotes like naloxone and flumazenil treat different overdoses and are not used for acetaminophen poisoning.