A 24-year-old man admitted for acute psychosis receives intramuscular haloperidol. Four hours later he develops torticollis, upward deviation of the eyes, and trismus. He is conscious and distressed. The most appropriate immediate treatment is:

• A Intravenous dantrolene and cooling
• B Oral propranolol
• C Intramuscular promethazine or another anticholinergic agent ✓
• D Reassurance only, as the reaction is self-limiting over days

Explanation

This is an acute dystonic reaction, an extrapyramidal side effect of high-potency D2 blockade, common in young males within hours to days of starting a typical antipsychotic. It resolves promptly with parenteral anticholinergics such as promethazine or trihexyphenidyl. Propranolol treats akathisia, not dystonia. Dantrolene is for neuroleptic malignant syndrome, which features rigidity, hyperthermia and autonomic instability rather than transient spasms. Waiting is inappropriate because laryngeal dystonia can threaten the airway.

Reference: Kaplan and Sadock's Synopsis of Psychiatry, 12th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.