Which of the following is an antidote for acetaminophen poisoning?

Appeared in: JODHPUR AIIMS SNO-2018

Explanation

N-Acetyl cysteine (NAC) is the specific antidote for acetaminophen (paracetamol) poisoning.
In an overdose, acetaminophen metabolism produces a toxic metabolite, N-acetyl-p-benzoquinone imine (NAPQI), which depletes liver glutathione stores and causes hepatocellular necrosis.
NAC acts as a glutathione precursor, replenishing hepatic glutathione levels.
Restored glutathione neutralizes the toxic NAPQI, preventing it from binding to and damaging liver cells.
Timely administration of NAC, ideally within 8 hours of ingestion, is crucial to prevent severe liver damage.

Option B: Deferoxamine is a chelating agent, which means it binds to metals. Its function is to bind with excess iron in the body.
Option C: Physostigmine is a cholinesterase inhibitor. It works by increasing the amount of acetylcholine at the cholinergic synapses.
Option D: Digibind is composed of antibody fragments that have a high affinity for digoxin.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Pharmacology: Antidotes for Common Poisonings as background academic context rather than a clinical decision trigger.
A nurse's rapid identification of potential acetaminophen toxicity and prompt initiation of the NAC protocol are critical to preventing irreversible liver failure.
Nurses must monitor for anaphylactoid reactions (a non-allergic hypersensitivity reaction) when administering IV N-Acetyl cysteine, which can cause flushing, rash, and sometimes bronchospasm. The infusion may need to be slowed or temporarily stopped.
Patient education is a key nursing role, emphasizing the dangers of exceeding the maximum daily dose of acetaminophen (4 grams for adults) and the importance of reading labels on combination cold and flu products that also contain acetaminophen.

How to Approach the Question

First, identify the core of the question, which is asking for the specific antidote for 'acetaminophen poisoning'.
This is a factual recall question common in pharmacology. Access your knowledge base about common poisons and their antidotes.
Systematically evaluate each option:
Option A: N-Acetyl cysteine. Recall its direct link to acetaminophen overdose treatment.
Option B: Deferoxamine. Associate this with iron poisoning.
Option C: Physostigmine. Link this to anticholinergic toxicity.

Concept Tested & Keywords

Q6y8pibWnJa18rmLahj8r8

E6 Pharmacology Katzung 16e p. 103-105

E6 Medicine Davidson Principles Practice 24e p. 158-160

E6 Nelson Textbook of Pediatrics(2024) — Volume 1 p. 755-757

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