Abstract
BACKGROUND: Recently, several new atypical antipsychotic agents have been introduced in Ontario, and regulatory warnings have been issued regarding use of atypical antipsychotics in older adults. We sought to establish the impact of newer atypical antipsychotics on prescribing rates and costs. METHODS: We performed a population-based cross-sectional study of Ontario adults aged 65 years or more using atypical antipsychotics from Jan. 1, 2007, to Mar. 31, 2013. These people have universal access to publicly funded drugs through the Ontario Health Insurance Plan and the Ontario Drug Benefit. We conducted time-series analysis to assess the impact of the introduction of new atypical antipsychotics on rates of use of atypical antipsychotics and associated expenditures. RESULTS: Rates of atypical antipsychotic use increased following the introduction of new agents in 2009, from 27.6 users per 1000 older adults in the third quarter of 2009 to 29.1 users per 1000 older adults at the end of the study period (p = 0.04). Although prescribing rates for the newer atypical agents (paliperidone, ziprasidone and aripiprazole) remained low relative to their older counterparts (risperidone, olanzapine and quetiapine), rates of aripiprazole use rose to 1.0 user per 1000 older adults by the end of the study period. The proportion of prescriptions that were for brand-name agents fell from 57.5% in the second quarter of 2007 to 6.1% in the second quarter of 2009, and then rose to 11.7% by the end of the study period. By the first quarter of 2013, newer atypical antipsychotic agents were used by 4.4% of atypical antipsychotic users but accounted for 14.1% ($1.2 million of $8.5 million) of atypical antipsychotic expenditures. INTERPRETATION: Although the overall prevalence of use of new atypical antipsychotic agents remains low, their introduction has led to increased prescribing of this class of drugs in older adults. Given the potential cost implications, further study of these trends would be prudent.