Rosh Emergency Medicine Practice Test 2025 - Free Emergency Medicine Practice Questions and Study Guide

N-acetylcysteine (NAC) is the specific antidote for acetaminophen overdose. Its primary mechanism is to replenish glutathione levels in the liver, which become depleted during acetaminophen toxicity. Acetaminophen is metabolized in the liver, and when taken in excessive amounts, it leads to the formation of harmful metabolites that can cause liver damage. NAC acts by providing cysteine, a precursor to glutathione, allowing for effective detoxification of these metabolites and thereby mitigating liver injury.

Furthermore, the timing of administration is crucial; NAC is most effective when given within 8-10 hours post-overdose but can still provide benefits when administered later. It can be given orally or intravenously, making it versatile for use in different clinical scenarios. Its use significantly improves outcomes for patients who have ingested toxic doses of acetaminophen.

Other choices, while potentially useful in certain contexts, do not serve as antidotes for acetaminophen toxicity. Narcotic analgesics might control pain but do not address the toxic effects of acetaminophen. Activated charcoal might be administered in the case of a recent overdose to reduce absorption but is not specific to counteracting the effects of acetaminophen itself. Flumazenil