Autonomic: neostigmine reversal of neuromuscular block: 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: neostigmine reversal of neuromuscular block

Sample item

At the end of surgery, a patient has residual neuromuscular block after vecuronium. Neostigmine is given with glycopyrrolate. Why is glycopyrrolate added?

ATo prevent tachyphylaxisBTo potentiate neuromuscular transmissionCTo prolong the action of neostigmineDTo block muscarinic effects such as bradycardia and salivation

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

The answer and the reasoning

D. To block muscarinic effects such as bradycardia and salivation

Neostigmine raises acetylcholine at nicotinic junctions, reversing non-depolarising block, but also at muscarinic sites, causing bradycardia, bronchospasm and secretions. An antimuscarinic such as glycopyrrolate or atropine blunts these effects.

Option by option

A. To prevent tachyphylaxis
Tachyphylaxis is not the reason for this combination.
B. To potentiate neuromuscular transmission
Glycopyrrolate has no role in enhancing neuromuscular transmission.
C. To prolong the action of neostigmine
It does not alter the duration of neostigmine action.
D. To block muscarinic effects such as bradycardia and salivation (correct)
Correct. The antimuscarinic offsets muscarinic side effects.

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.

Questions about this Pharmacology question

What is the answer to this Pharmacology question?

The best answer is D, To block muscarinic effects such as bradycardia and salivation. Neostigmine raises acetylcholine at nicotinic junctions, reversing non-depolarising block, but also at muscarinic sites, causing bradycardia, bronchospasm and secretions.

Why is "To prevent tachyphylaxis" not the answer?

Tachyphylaxis is not the reason for this combination.

Why is "To potentiate neuromuscular transmission" not the answer?

Glycopyrrolate has no role in enhancing neuromuscular transmission.

Why is "To prolong the action of neostigmine" not the answer?

It does not alter the duration of neostigmine action.

What concept does this question test?

It tests Autonomic: neostigmine reversal of neuromuscular block in Pharmacology. An antimuscarinic such as glycopyrrolate or atropine blunts these effects.

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: neostigmine reversal of neuromuscular block?

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.