What is the antidote for acetaminophen overdose?

• A. Dialysis only.
• B. Administer benzodiazepines.
• C. Induce vomiting.
• D. Administer N-acetylcysteine.

Answer: (D)

The key idea is that restoring glutathione to detoxify the toxic metabolite of acetaminophen is what prevents liver injury. In an overdose, more acetaminophen is pushed through the cytochrome P450 pathway to form NAPQI, a highly reactive compound. Glutathione normally neutralizes NAPQI, but stores become depleted during overdose, allowing NAPQI to damage liver cells.

N-acetylcysteine supplies a sulfhydryl group that replenishes hepatic glutathione and helps detoxify NAPQI, directly protecting the liver. It’s most effective when given early, ideally within about 8–10 hours, though it can still provide benefit later. It can be given orally or by IV, depending on the situation.

Other options don’t address the underlying toxic mechanism: dialysis is not a specific antidote for acetaminophen toxicity, benzodiazepines treat symptoms like agitation or seizures but don’t prevent hepatotoxicity, and inducing vomiting is unsafe and ineffective at preventing damage.