Toxicology: paracetamol poisoning: practice question

A Pharmacology question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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Pharmacology · Toxicology: paracetamol poisoning

Sample item

A young woman presents 6 hours after ingesting 20 g of paracetamol. Which treatment is indicated, and what guides the decision?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

C. N-acetylcysteine, guided by the plasma level plotted on the treatment nomogram from 4 hours

N-acetylcysteine replenishes glutathione and binds the toxic metabolite NAPQI, and it is most effective when started within 8 to 10 hours of ingestion. The Rumack-Matthew nomogram uses a level taken at 4 hours or later, and unknown-time ingestion is treated empirically.

Option by option

  • A. Fomepizole

    Fomepizole treats methanol and ethylene glycol poisoning.

  • B. Flumazenil

    Flumazenil reverses benzodiazepines.

  • C. N-acetylcysteine, guided by the plasma level plotted on the treatment nomogram from 4 hours (correct)

    Correct. NAC guided by the nomogram.

  • D. Naloxone

    Naloxone reverses opioids.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

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Questions about this Pharmacology question

What is the answer to this Pharmacology question?

The best answer is C, N-acetylcysteine, guided by the plasma level plotted on the treatment nomogram from 4 hours. N-acetylcysteine replenishes glutathione and binds the toxic metabolite NAPQI, and it is most effective when started within 8 to 10 hours of ingestion.

Why is "Fomepizole" not the answer?

Fomepizole treats methanol and ethylene glycol poisoning.

Why is "Flumazenil" not the answer?

Flumazenil reverses benzodiazepines.

Why is "Naloxone" not the answer?

Naloxone reverses opioids.

What concept does this question test?

It tests Toxicology: paracetamol poisoning in Pharmacology. The Rumack-Matthew nomogram uses a level taken at 4 hours or later, and unknown-time ingestion is treated empirically.

How hard is this question?

We tag it as a multi-step question: it asks you to combine more than one idea. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Toxicology: paracetamol poisoning?

Learn drugs as classes, then the exception in each class that an examiner would pick. Then use the flashcards and the other Pharmacology questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.