Antifungals: azole mechanism and ketoconazole: 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 · Antifungals: azole mechanism and ketoconazole

Sample item

A man with prostate cancer is treated with high-dose ketoconazole and develops gynaecomastia and low cortisol. What is the explanation?

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

The answer and the reasoning

D. Inhibition of fungal and human cytochrome P450 enzymes involved in steroid synthesis

Azoles inhibit fungal lanosterol 14-alpha-demethylase, but ketoconazole also inhibits human enzymes in adrenal and gonadal steroid synthesis, lowering testosterone and cortisol. It also inhibits CYP3A4 and requires an acidic gastric pH.

Option by option

  • A. Blockade of ergosterol binding

    Binding to ergosterol describes polyenes.

  • B. Inhibition of beta-glucan synthase

    Beta-glucan synthase is the echinocandin target.

  • C. Direct androgen receptor agonism

    It is not an androgen agonist.

  • D. Inhibition of fungal and human cytochrome P450 enzymes involved in steroid synthesis (correct)

    Correct. Ketoconazole blocks human steroidogenic enzymes.

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 D, Inhibition of fungal and human cytochrome P450 enzymes involved in steroid synthesis. Azoles inhibit fungal lanosterol 14-alpha-demethylase, but ketoconazole also inhibits human enzymes in adrenal and gonadal steroid synthesis, lowering testosterone and cortisol.

Why is "Blockade of ergosterol binding" not the answer?

Binding to ergosterol describes polyenes.

Why is "Inhibition of beta-glucan synthase" not the answer?

Beta-glucan synthase is the echinocandin target.

Why is "Direct androgen receptor agonism" not the answer?

It is not an androgen agonist.

What concept does this question test?

It tests Antifungals: azole mechanism and ketoconazole in Pharmacology. It also inhibits CYP3A4 and requires an acidic gastric pH.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. 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 Antifungals: azole mechanism and ketoconazole?

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.