Cholinergic drugs: pilocarpine in angle closure: 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 · Cholinergic drugs: pilocarpine in angle closure

Sample item

A 60-year-old woman has a painful red eye, a mid-dilated fixed pupil, corneal haze and intraocular pressure of 58 mmHg. After intravenous acetazolamide and mannitol, which topical drug is used to open the angle?

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

The answer and the reasoning

A. Pilocarpine

In acute angle closure the peripheral iris blocks the trabecular meshwork. Pilocarpine contracts the sphincter pupillae, constricting the pupil and pulling the iris away from the angle, and it is given once pressure has begun to fall since the ischaemic sphincter responds poorly at very high pressures. Mydriatics are contraindicated.

Option by option

  • A. Pilocarpine (correct)

    Correct. Miosis draws the peripheral iris out of the angle.

  • B. Phenylephrine

    Phenylephrine is a mydriatic and would crowd the angle further.

  • C. Atropine

    Atropine causes mydriasis and cycloplegia and can precipitate angle closure.

  • D. Tropicamide

    Tropicamide dilates the pupil and can worsen angle closure.

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 A, Pilocarpine. In acute angle closure the peripheral iris blocks the trabecular meshwork.

Why is "Phenylephrine" not the answer?

Phenylephrine is a mydriatic and would crowd the angle further.

Why is "Atropine" not the answer?

Atropine causes mydriasis and cycloplegia and can precipitate angle closure.

Why is "Tropicamide" not the answer?

Tropicamide dilates the pupil and can worsen angle closure.

What concept does this question test?

It tests Cholinergic drugs: pilocarpine in angle closure in Pharmacology. Pilocarpine contracts the sphincter pupillae, constricting the pupil and pulling the iris away from the angle, and it is given once pressure has begun to fall since the ischaemic sphincter responds poorly at very high pressures. Mydriatics are contraindicated.

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 Cholinergic drugs: pilocarpine in angle closure?

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.