Antimicrobials: carbapenem-resistant organisms: 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 · Antimicrobials: carbapenem-resistant organisms

Sample item

A patient in an Indian ICU has bacteraemia with a carbapenem-resistant Klebsiella carrying NDM-1 metallo-beta-lactamase. Which option is a recognised treatment approach?

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

The answer and the reasoning

B. Colistin-based or aztreonam combined with ceftazidime-avibactam

Metallo-beta-lactamases hydrolyse carbapenems and are not inhibited by avibactam, so aztreonam (stable to MBL) combined with ceftazidime-avibactam is used, with colistin and tigecycline as other options. India has a high NDM-1 prevalence.

Option by option

  • A. Ceftriaxone alone

    Ceftriaxone is hydrolysed.

  • B. Colistin-based or aztreonam combined with ceftazidime-avibactam (correct)

    Correct. These are recognised options for NDM producers.

  • C. Amoxicillin-clavulanate

    Amoxicillin-clavulanate is ineffective.

  • D. Meropenem at higher doses alone

    Carbapenems are hydrolysed by NDM.

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 B, Colistin-based or aztreonam combined with ceftazidime-avibactam. Metallo-beta-lactamases hydrolyse carbapenems and are not inhibited by avibactam, so aztreonam (stable to MBL) combined with ceftazidime-avibactam is used, with colistin and tigecycline as other options.

Why is "Ceftriaxone alone" not the answer?

Ceftriaxone is hydrolysed.

Why is "Amoxicillin-clavulanate" not the answer?

Amoxicillin-clavulanate is ineffective.

Why is "Meropenem at higher doses alone" not the answer?

Carbapenems are hydrolysed by NDM.

What concept does this question test?

It tests Antimicrobials: carbapenem-resistant organisms in Pharmacology. India has a high NDM-1 prevalence.

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 Antimicrobials: carbapenem-resistant organisms?

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.