Antimicrobials: pentamidine toxicity: 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: pentamidine toxicity

Sample item

An HIV-positive man with severe Pneumocystis pneumonia and a sulfonamide allergy is treated with an intravenous drug. On day 5 he has hypoglycaemia, followed by hyperglycaemia, and a raised serum amylase. Which drug is the likely cause?

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

The answer and the reasoning

B. Pentamidine

Pentamidine is toxic to pancreatic beta cells, releasing insulin and causing hypoglycaemia, and later destroying the cells and causing diabetes. It also causes pancreatitis, nephrotoxicity and QT prolongation. It is an alternative in sulfonamide allergy.

Option by option

  • A. Atovaquone

    Atovaquone is oral and its main adverse effects are rash and gastrointestinal upset.

  • B. Pentamidine (correct)

    Correct. Beta-cell toxicity gives hypoglycaemia then diabetes, with pancreatitis.

  • C. Clindamycin with primaquine

    Clindamycin with primaquine causes diarrhoea and haemolysis in G6PD deficiency, not dysglycaemia.

  • D. Dapsone with trimethoprim

    Dapsone with trimethoprim causes haemolysis and methaemoglobinaemia.

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.

More Pharmacology questions

Questions about this Pharmacology question

What is the answer to this Pharmacology question?

The best answer is B, Pentamidine. Pentamidine is toxic to pancreatic beta cells, releasing insulin and causing hypoglycaemia, and later destroying the cells and causing diabetes.

Why is "Atovaquone" not the answer?

Atovaquone is oral and its main adverse effects are rash and gastrointestinal upset.

Why is "Clindamycin with primaquine" not the answer?

Clindamycin with primaquine causes diarrhoea and haemolysis in G6PD deficiency, not dysglycaemia.

Why is "Dapsone with trimethoprim" not the answer?

Dapsone with trimethoprim causes haemolysis and methaemoglobinaemia.

What concept does this question test?

It tests Antimicrobials: pentamidine toxicity in Pharmacology. It also causes pancreatitis, nephrotoxicity and QT prolongation. It is an alternative in sulfonamide allergy.

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: pentamidine toxicity?

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.