Background: Naturalistic studies offer advantages over randomized clinical trials by including patients seen in routine practice. Aripiprazole and quetiapine are the most recent second-generation antipsychotics available in the United Kingdom. We aimed to study all patients who were prescribed these medications in a defined geographic area in order to identify and compare those who had a good clinical response.
Method: We conducted an electronic chart review of a sample of all people attending secondary mental health care in the county of Lanarkshire, Scotland, who were treated with aripiprazole or quetiapine for schizophrenia and related psychoses (ICD-10 criteria) between 2002 and 2007. To measure effectiveness, we retrospectively assigned Clinical Global Impressions (CGI) scores and examined medication discontinuation rates.
Results: Eighty-nine patients were started on treatment with aripiprazole and 132 patients with quetiapine over the 5-year period. Those treated with quetiapine had a higher initial illness severity (CGI-Severity of Illness scale) (p = .0003), were more likely to be starting rather than switching antipsychotics (p = .0003), were more likely to have a mood disorder (p = .03), were less likely to be treatment resistant (p = .005), and had lower rates of prescription of additional antipsychotics (p = .009). After adjusting for these variables, the proportions who improved according to CGI were 74% with aripiprazole and 67% with quetiapine. Overall medication discontinuation rates were also similar, 42% for aripiprazole and 45% for quetiapine, with early discontinuation of aripiprazole being noticeable, often due to agitation (13% of all patients treated with the drug).
Conclusions: Despite their different pharmacologic properties, aripiprazole and quetiapine were similarly effective in the majority of patients. Early discontinuation of aripiprazole due to agitation was an important finding.
Copyright 2009 Physicians Postgraduate Press, Inc.