Factors in second-generation antipsychotic switching patterns in a national sample of older veterans with schizophrenia

Objective: A 2004 consensus statement by the American Psychiatric Association and other groups noted that metabolic side effects of second-generation antipsychotics require monitoring. To reduce risk, prescribers may consider factors differentially associated with development of metabolic abnormalities, such as age, gender, and race-ethnicity. As part of a study of older patients with schizophrenia (50-102 years), this study evaluated factors associated with antipsychotic switches and switches that incurred a greater or lesser metabolic risk. Methods: Administrative data were analyzed for a national cohort of 16,103 Veterans Health Administration patients with schizophrenia receiving second-generation antipsychotics. Multinomial logistic regression predicted the likelihood of switches from 2002 to 2003 and again from 2004 to 2005. Results: At baseline nearly half the patients (45%) had a diagnosis of hypertension, a third (34%) had dyslipidemia, and 15% had a diagnosis of obesity. In both periods diabetes was associated with switches to lower-risk antipsychotics, and older patients were likely to experience neutral or no switches. Women were more likely to experience switches to higher-risk antipsychotics in 2004-2005. Conclusions: General medical conditions potentially associated with antipsychotic-related metabolic concerns were common; however, half of these patients were prescribed medication that made them liable to developing metabolic problems. Modest evidence suggests that metabolic considerations became a higher priority during the study. Future research should investigate the differential impact of antipsychotics on metabolic dysregulation for women and elderly patients. Findings underscore the need to monitor metabolic parameters of older patients taking antipsychotics.