Risk of extrapyramidal syndrome in schizophrenic patients treated with antipsychotics: a population-based study

Clin Pharmacol Ther. 2007 Apr;81(4):586-94. doi: 10.1038/sj.clpt.6100069. Epub 2007 Jan 18.


To compare the prevalence of extrapyramidal syndrome (EPS) between the first-generation antipsychotics (FGAs) and second-generation antipsychotics (SGAs), the co-prescribing rate of anti-Parkinson drugs (APDs) of each antipsychotic drug was analyzed using population database. Fourteen antipsychotics had been prescribed during the 5-year study period. Among the SGAs, quetiapine had the lowest crude co-prescribing rate of APDs (27.09%), whereas risperidone had the highest rate (66.50%). Among the FGAs, thioridazine and loxapine had the lowest (60.99%) and highest rates (96.35%), respectively. The rankings of the co-prescribing rate of APDs among antipsychotics, in increasing order, were quetiapine, clozapine, olanzapine, thioridazine, zotepine, chlorpromazine, risperidone, sulpiride, clotiapine, flupentixol, haloperidol, zuclopentixol, trifluoperazine, and loxapine. The results indicate that the risk of EPS appears to be lower in SGAs than in FGAs; however, the considerably high rate of EPS in some of the newer generation of antipsychotics warrants clinical attention.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Anti-Dyskinesia Agents / therapeutic use
  • Antidepressive Agents / adverse effects
  • Antidepressive Agents / therapeutic use
  • Antimanic Agents / adverse effects
  • Antimanic Agents / therapeutic use
  • Antipsychotic Agents / adverse effects*
  • Drug Utilization
  • Dyskinesia, Drug-Induced / drug therapy
  • Dyskinesia, Drug-Induced / epidemiology*
  • Female
  • Humans
  • Hypnotics and Sedatives / adverse effects
  • Hypnotics and Sedatives / therapeutic use
  • Male
  • National Health Programs / statistics & numerical data
  • Population
  • Risk
  • Schizophrenia / complications*
  • Taiwan / epidemiology


  • Anti-Dyskinesia Agents
  • Antidepressive Agents
  • Antimanic Agents
  • Antipsychotic Agents
  • Hypnotics and Sedatives