dystonic reaction
An acute neurological side effect of antipsychotic medications characterized by involuntary muscle contractions and spasms.
Full Definition
A dystonic reaction is an acute, involuntary movement disorder caused by dopamine receptor blockade from antipsychotic medications, particularly typical antipsychotics and high-potency agents. These reactions typically occur within hours to days of medication initiation or dose increases and manifest as sustained muscle contractions, abnormal postures, or spasms affecting various muscle groups. Common presentations include oculogyric crisis (upward eye deviation), torticollis (neck twisting), opisthotonus (back arching), and laryngeal dystonia. Dystonic reactions are medical emergencies when they affect breathing or swallowing and are typically treated with anticholinergic medications such as benztropine or diphenhydramine.
Usage
Usage note: Hyphenate when used as compound adjective; distinguish from tardive dyskinesia by timing and reversibility.
In Context
- "The patient developed an acute dystonic reaction 12 hours after starting haloperidol therapy." — Adverse event report
- "Benztropine 2 mg intramuscularly provided rapid relief of the dystonic reaction within 15 minutes." — Emergency treatment documentation