1. ¹Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
2. ²Department of Pharmacy, Tsyr-Huey Mental Hospital, Kaohsiung, Taiwan
3. ³Institute of Clinical Pharmacy, National Cheng Kung University, Tainan, Taiwan
4. ⁴Department of Psychiatry, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan
5. ⁵Chang Gung University, Taipei, Taiwan
6. ⁶Statistical Analysis Laboratory, Department of Clinical Research, Kaohsiung Medical University, Kaohsiung, Taiwan
7. ⁷Department of Psychiatry, Tzu Chi University, Hualien, Taiwan

Correspondence: Y-H Kao Yang, (yhkao@mail.ncku.edu.tw)

Received 13 September 2006; Accepted 15 November 2006; Published online 18 January 2007.

Abstract

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.