Psychopharmacology adverse effects: acute dystonia: practice question

A Psychiatry 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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Psychiatry · Psychopharmacology adverse effects: acute dystonia

Sample item

A 19-year-old man given an intramuscular haloperidol injection two hours earlier now has a twisted neck, a clenched jaw and upward deviation of the eyes. He is frightened but conscious. What is the best treatment?

AIntravenous phenytoinBIntravenous dantroleneCIncrease the dose of haloperidolDIntramuscular or intravenous anticholinergic such as procyclidine or benztropine

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

The answer and the reasoning

D. Intramuscular or intravenous anticholinergic such as procyclidine or benztropine

Acute dystonia is an early extrapyramidal reaction to dopamine antagonists, typically within hours to days, more often in young men and with high-potency agents. It is relieved within minutes by parenteral anticholinergics, with benzodiazepines or promethazine as alternatives. Prophylaxis or a lower-risk antipsychotic is considered afterwards.

Option by option

A. Intravenous phenytoin
Phenytoin has no role in drug-induced dystonia.
B. Intravenous dantrolene
Dantrolene is used for neuroleptic malignant syndrome and malignant hyperthermia.
C. Increase the dose of haloperidol
More haloperidol would worsen the dystonia.
D. Intramuscular or intravenous anticholinergic such as procyclidine or benztropine (correct)
Correct. An anticholinergic restores the dopamine-acetylcholine balance and relieves the spasm.

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 Psychiatry question

What is the answer to this Psychiatry question?

The best answer is D, Intramuscular or intravenous anticholinergic such as procyclidine or benztropine. Acute dystonia is an early extrapyramidal reaction to dopamine antagonists, typically within hours to days, more often in young men and with high-potency agents.

Why is "Intravenous phenytoin" not the answer?

Phenytoin has no role in drug-induced dystonia.

Why is "Intravenous dantrolene" not the answer?

Dantrolene is used for neuroleptic malignant syndrome and malignant hyperthermia.

Why is "Increase the dose of haloperidol" not the answer?

More haloperidol would worsen the dystonia.

What concept does this question test?

It tests Psychopharmacology adverse effects: acute dystonia in Psychiatry. It is relieved within minutes by parenteral anticholinergics, with benzodiazepines or promethazine as alternatives. Prophylaxis or a lower-risk antipsychotic is considered afterwards.

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 Psychopharmacology adverse effects: acute dystonia?

Learn each diagnosis by its core features and its first-line treatment. Then use the flashcards and the other Psychiatry 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.