Which antidote can be used for acetaminophen poisoning if given early?

• A. Flumazenil
• B. N-acetylcysteine (NAC)
• C. Atropine
• D. Activated charcoal

Answer: (B)

N-acetylcysteine (NAC) is the antidote of choice for acetaminophen poisoning when administered early. It works by replenishing glutathione levels in the liver, which helps detoxify the harmful metabolites of acetaminophen. Early treatment with NAC is crucial because it can significantly reduce the risk of liver damage and improve outcomes for the patient.

NAC acts by conjugating with the toxic metabolite N-acetyl-p-benzoquinone imine (NAPQI), which is produced when acetaminophen is metabolized. This mechanism helps protect hepatocytes from injury and promotes recovery. For the best effect, NAC should ideally be given within 8-10 hours of acetaminophen ingestion, but it can still be beneficial if administered later.

Other choices are not appropriate for treating acetaminophen poisoning, as they serve different purposes. Flumazenil is a benzodiazepine antagonist and is not indicated for acetaminophen toxicity. Atropine is an anticholinergic agent primarily used in cases of cholinergic poisoning, and activated charcoal may be used to limit absorption of the toxin if administered within a relevant timeframe, but it does not counteract the effects of acetaminophen directly like NAC does