Emergency and critical care: Amanita phalloides poisoning: practice question

A General Medicine 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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General Medicine · Emergency and critical care: Amanita phalloides poisoning

Sample item

Eight hours after a family meal of wild mushrooms, a woman has severe vomiting and watery diarrhoea that settles for a day. On day 3 she has jaundice, coagulopathy and rising transaminases. Which is the mechanism of the toxin responsible?

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

The answer and the reasoning

C. Inhibition of RNA polymerase II

Amatoxins from Amanita phalloides inhibit RNA polymerase II, stopping protein synthesis in hepatocytes. Symptoms appear after a delay of 6 to 24 hours, followed by an apparently recovering phase and then liver failure. Treatment includes fluids, activated charcoal, silibinin or acetylcysteine and transplantation when needed.

Option by option

  • A. Blockade of muscarinic receptors

    Muscarinic receptor blockade describes Datura and belladonna poisoning.

  • B. Inhibition of acetylcholinesterase

    Acetylcholinesterase inhibition describes organophosphates and some Clitocybe toxins.

  • C. Inhibition of RNA polymerase II (correct)

    Correct. Amatoxin blocks mRNA synthesis and kills hepatocytes.

  • D. Inhibition of mitochondrial complex IV

    Complex IV inhibition describes cyanide.

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 General Medicine question

What is the answer to this General Medicine question?

The best answer is C, Inhibition of RNA polymerase II. Amatoxins from Amanita phalloides inhibit RNA polymerase II, stopping protein synthesis in hepatocytes.

Why is "Blockade of muscarinic receptors" not the answer?

Muscarinic receptor blockade describes Datura and belladonna poisoning.

Why is "Inhibition of acetylcholinesterase" not the answer?

Acetylcholinesterase inhibition describes organophosphates and some Clitocybe toxins.

Why is "Inhibition of mitochondrial complex IV" not the answer?

Complex IV inhibition describes cyanide.

What concept does this question test?

It tests Emergency and critical care: Amanita phalloides poisoning in General Medicine. Symptoms appear after a delay of 6 to 24 hours, followed by an apparently recovering phase and then liver failure. Treatment includes fluids, activated charcoal, silibinin or acetylcysteine and transplantation when needed.

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 Emergency and critical care: Amanita phalloides poisoning?

For each disease know the classic presentation, the best test, and the first-line treatment. Then use the flashcards and the other General Medicine 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.