Quetiapine for Patients with Agitation or Psychosis Related to Alzheimer's Disease and Vascular Dementia

Abstract

Objectives: More and more elderly people around the world suffer from dementia and its related behavioral and psychological symptoms. Second generation antipsychotic agents, including quetiapine, are frequently used for patients with dementia-associated agitation or psychosis. However, existing data about effective dose of antipsychotics are mostly drawn from researches focusing on Caucasian patients with Alzheimer's disease (AD). We accordingly conducted a retrospective study via chart review in a medical center in Taiwan to find out the optimal dose of quetiapine for outpatients with agitation or psychosis related to AD or vascular dementia (VaD). Methods: Lists of candidate patients were retrieved from the database of a medical center in Taiwan based on their ICD-9 codes and prescription records of antipsychotics obtained from the center's neurology or psychiatry departments during 2006 and 2007. The candidate patients' medical charts were then reviewed, and their data entered into final analysis when the following inclusion criteria were met: (1). diagnosis of AD or VaD; (2). prescription of quetiapine exclusively for agitation or psychosis related to dementia; and (3). achievement of ”stable state” defined as a period when a constant dose of quetiapine had been maintained for at least 4 weeks during which there had been at least two visits at an interval of more than four weeks. The constant dose during stable state was defined as the ”optimal dose” in this study. Optimal doses of the AD group and VaD group were calculated and compared with each other. The relationships between optimal dose and clinical correlates within each group were examined. Results: A total of 118 patients (75 females, mean [SD] age 77.8 [7.3] years) was included. Forty-nine patients had AD and 69 had VaD. The demographic data and clinical correlates were similar between the two groups, except that more patients with AD took cognitive enhancers. The mean daily optimal dose of quetiapine was not significantly different between the AD patients (38.5 [37.8] mg) and their VaD counterparts (45.7 [69.9] mg). Patients with greater severity required significantly higher dose of quetiapine. Age, gender or symptom profiles were not significantly associated with optimal dose in either group. Conclusion: For patients with VaD related agitation or psychosis, the daily optimal dose was similar to that of patients with AD. Compared to previous studies regarding Caucasian patients, our data showed a relatively lower optimal daily dose of quetiapine for dementia-related psychosis or agitation in Chinese/Taiwanese patients.