Extrapyramidal reaction

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  • Adverse effect of antipsychotics.
  • More common with high-potency typical antipsychotics, but can also occur with atypical agents
  • Due to antagonism of dopamine-2 receptors in basal ganglia

Clinical Features

  • Early-onset syndromes
    • hours to days after drug initiation
    • reversible
    • Acute dystonic reaction
      • involuntary, uncoordinated skelatal muscle contraction
    • Akathisia
      • subjective sensation of intense motor restlessness
      • may be misdiagnosed as manifestation of psychiatric disease
  • Parkinsonism
    • onset weeks to months after starting medication
    • similar presentation to Parkinson's disease (e.g. cogwheel rigidity, pill-rolling tremor, shuffling gait, bradykinesia)
  • Tardive dyskinesia
    • usually irreversible or only partially reversible
    • associated with prolonged use of antipsychotics
    • stereotyped, repetitive facial movements (e.g. tongue protrusion, grimacing, lip smacking)

Differential Diagnosis

Movement Disorders and Other Abnormal Contractions



  • Stop or reduce offending agent
    • may need to discuss with psychiatrist to prescribe new medication or for recs on taper
  • Acute dystonia, akasthisia, parkinsonism
  • Tardive dyskinesia
    • may only be partially reversible, so minimize occurrence, stop or reduce offending agent promptly
    • Do NOT give anticholinergics, will exacerbate symptoms


See Also

External Links