Autonomic nervous system: antimuscarinics and angle-closure glaucoma: 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 · Autonomic nervous system: antimuscarinics and angle-closure glaucoma

Sample item

An elderly woman with a shallow anterior chamber is given a drug for motion sickness and develops severe eye pain, halos around lights and a mid-dilated pupil. Which drug was most likely given?

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

The answer and the reasoning

C. Hyoscine

Hyoscine is a centrally acting antimuscarinic that dilates the pupil. In a narrow anterior chamber, the bunched iris blocks drainage of aqueous humour and precipitates acute angle-closure glaucoma.

Option by option

  • A. Pantoprazole

    Pantoprazole is a proton pump inhibitor with no effect on pupil size.

  • B. Metoclopramide

    Metoclopramide is a dopamine antagonist and prokinetic that does not dilate the pupil.

  • C. Hyoscine (correct)

    Correct. The antimuscarinic causes mydriasis that blocks the drainage angle.

  • D. Domperidone

    Domperidone is a peripheral dopamine antagonist without antimuscarinic action.

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 C, Hyoscine. Hyoscine is a centrally acting antimuscarinic that dilates the pupil.

Why is "Pantoprazole" not the answer?

Pantoprazole is a proton pump inhibitor with no effect on pupil size.

Why is "Metoclopramide" not the answer?

Metoclopramide is a dopamine antagonist and prokinetic that does not dilate the pupil.

Why is "Domperidone" not the answer?

Domperidone is a peripheral dopamine antagonist without antimuscarinic action.

What concept does this question test?

It tests Autonomic nervous system: antimuscarinics and angle-closure glaucoma in Pharmacology. In a narrow anterior chamber, the bunched iris blocks drainage of aqueous humour and precipitates acute angle-closure glaucoma.

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 Autonomic nervous system: antimuscarinics and angle-closure glaucoma?

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.