Autonomic nervous system: 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 nervous system: reversal of neuromuscular block

Sample item

At the end of surgery an anaesthetist reverses vecuronium with neostigmine and also gives glycopyrrolate. Why is the glycopyrrolate given?

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

The answer and the reasoning

D. To block muscarinic effects of neostigmine

Neostigmine raises acetylcholine at both nicotinic and muscarinic sites. An antimuscarinic such as glycopyrrolate prevents bradycardia, salivation and bronchospasm without reversing the nicotinic benefit at the motor end plate.

Option by option

  • A. To potentiate the nicotinic action of neostigmine

    Glycopyrrolate has no action to enhance nicotinic effects.

  • B. To prolong the neuromuscular block

    Prolonging the block would defeat the purpose of reversal.

  • C. To prevent malignant hyperthermia

    Dantrolene, not glycopyrrolate, is used for malignant hyperthermia.

  • D. To block muscarinic effects of neostigmine (correct)

    Correct. It blocks muscarinic effects such as bradycardia and secretions.

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, To block muscarinic effects of neostigmine. Neostigmine raises acetylcholine at both nicotinic and muscarinic sites.

Why is "To potentiate the nicotinic action of neostigmine" not the answer?

Glycopyrrolate has no action to enhance nicotinic effects.

Why is "To prolong the neuromuscular block" not the answer?

Prolonging the block would defeat the purpose of reversal.

Why is "To prevent malignant hyperthermia" not the answer?

Dantrolene, not glycopyrrolate, is used for malignant hyperthermia.

What concept does this question test?

It tests Autonomic nervous system: reversal of neuromuscular block in Pharmacology. An antimuscarinic such as glycopyrrolate prevents bradycardia, salivation and bronchospasm without reversing the nicotinic benefit at the motor end plate.

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: 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.