Changes in antipsychotic use among patients with severe mental illness after a Food and Drug Administration advisory

Abstract

Purpose: A 2003 Food and Drug Administration advisory warned of increased hyperlipidemia and diabetes risk for patients taking second-generation antipsychotics (SGAs). After the advisory, a professional society consensus statement provided treatment recommendations and stratified SGAs into high, intermediate, and low metabolic risk. We examine subsequent changes in incident and prevalent SGA use among individuals with severe mental illness.

Methods: We created a retrospective cohort using Florida Medicaid's claims from 2001 to 2006. We included non-Medicare eligible adults with bipolar disorder or schizophrenia who filled an SGA prescription. We assessed changes in overall and agent-specific use, discontinuations, interruptions, and therapeutic alternative use among prevalent users and agent-specific use among incident users. Pre-advisory utilization was compared with utilization initially after the advisory and two subsequent periods.

Results: Among prevalent users, overall SGA use decreased slightly, and no increases in treatment interruptions or discontinuations were observed after the advisory and consensus statement publication. Compared with the pre-advisory period, in the months immediately after the advisory, the use of the highest metabolic-risk agent, olanzapine, decreased by 34% among prevalent users with bipolar disorder (adjusted risk ratio [aRR] = 0.66, 95%CI = 0.59-0.74) and 26% among prevalent users with schizophrenia (aRR = 0.74, 95%CI = 0.72-0.76). A greater decrease was estimated among incident users with bipolar disorder (aRR = 0.37, 95%CI = 0.29-0.47) and schizophrenia (aRR = 0.42, 95%CI = 0.35-0.51) during this period. During each subsequent post-advisory period, olanzapine use continued to decrease whereas quetiapine, ziprasidone, and aripiprazole use increased.

Conclusions: The metabolic risk advisory and the published consensus statement were associated with a selective reduction in olanzapine use without evidence of treatment disruptions among this population.

Figure 1. Atypical Antipsychotic Market Share among Prior Olanzapine Users

P/C/D = Period including the Medicaid Preferred-Drug List policy change, publication of the CATIE trial results, and the FDA’s black box warning for the risk of mortality among elderly patients with dementia.