Autacoids and NSAIDs: 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 · Autacoids and NSAIDs

Sample item

What is the mechanism of action of aspirin?

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

The answer and the reasoning

B. Irreversible inhibition of cyclo-oxygenase

Aspirin acetylates cyclo-oxygenase irreversibly. Platelets cannot make new enzyme, so thromboxane A2 production stays suppressed for the 7 to 10 days of platelet life, which underlies low-dose antiplatelet use. Other NSAIDs inhibit COX reversibly.

Option by option

  • A. Inhibition of 5-lipoxygenase

    Zileuton inhibits 5-lipoxygenase.

  • B. Irreversible inhibition of cyclo-oxygenase (correct)

    Correct. Acetylation permanently inactivates COX, and platelets cannot regenerate it.

  • C. Inhibition of phospholipase A2

    Corticosteroids, through lipocortin, inhibit phospholipase A2.

  • D. Reversible selective COX-2 inhibition

    Selective reversible COX-2 inhibition describes coxibs, not aspirin.

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, Irreversible inhibition of cyclo-oxygenase. Aspirin acetylates cyclo-oxygenase irreversibly.

Why is "Inhibition of 5-lipoxygenase" not the answer?

Zileuton inhibits 5-lipoxygenase.

Why is "Inhibition of phospholipase A2" not the answer?

Corticosteroids, through lipocortin, inhibit phospholipase A2.

Why is "Reversible selective COX-2 inhibition" not the answer?

Selective reversible COX-2 inhibition describes coxibs, not aspirin.

What concept does this question test?

It tests Autacoids and NSAIDs in Pharmacology. Platelets cannot make new enzyme, so thromboxane A2 production stays suppressed for the 7 to 10 days of platelet life, which underlies low-dose antiplatelet use. Other NSAIDs inhibit COX reversibly.

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 Autacoids and NSAIDs?

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.