The use of antipsychotics in patients with Parkinson's Disease at Auckland City Hospital

Abstract

Introduction There is limited randomised controlled evidence regarding the use of antipsychotic medications in PD patients with psychosis. The American Academy of Neurology consider clozapine first line treatment for psychosis in PD. In practice, patients are typically treated with quetiapine initially due to concern about side effects, and changed to clozapine if they fail this. We aimed to review the use of antipsychotics in patients with PD and the demographics of PD patients who develop psychosis. Methods Patients with PD on antipsychotic medications were identified by the Movement Disorder nurse specialist database and by reviewing patients admitted to Auckland City Hospital from January 2006 until March 2008. The demographic data, details of PD and antipsychotic use and comorbidities were recorded. Results Sixty-six patients with PD on antipsychotics were identified; 42 (64%) were men. The median age was 78 years and 48 (73%) were in residential care. All patients were on levodopa treatment (with 26 (39%) also on additional treatment). Fifty-two patients were treated with quetiapine, 12 with clozapine, and 3 with other agents. The most common indication for use was hallucinations. Thirty one (47%) had history of cognitive impairment. Fifty percent of patients on clozapine had previously failed quetiapine. Absolute failure rate of quetiapine was calculated at 12 %. Patients on clozapine had less comorbidity. It was well tolerated with no episodes of leukopenia. Conclusion Quetiapine has a reasonable efficacy rate with minimal side effects. This review lends support to the assumption that quetiapine is a useful medication. However clozapine also was well tolerated and could be considered for use more frequently than it is.