Impact of safety warnings on antipsychotic prescriptions in dementia: nothing has changed but the years and the substances

Abstract

Dementia patients suffering from behavioral and psychological symptoms (BPSD) are often treated with antipsychotics. Trial results document an increased risk for serious adverse events and mortality in dementia patients taking these agents. Furthermore, the efficacy of treating BPSD with antipsychotics seems to be only modest. Using data of a German statutory health insurance company, we examined prescription trends of antipsychotics in prevalent dementia patients in the context of official warnings. The study period is 2004-2009. We studied trends in demographics, age and sex, as well as need of care and the intake of typical and atypical antipsychotics. Seeking for linear trends adjusted for age, sex and level of care between 2004 and 2009, we obtained p-values from a multivariate logistic regression. Prescription volumes were calculated by number of packages as well as defined daily doses (DDDs) using multiple linear regressions for trends in prescriptions amount. We included 3460-8042 patients per year (mean age 80 years). The prescription prevalence of antipsychotics decreased from 35.5% in 2004 to 32.5% in 2009 (multivariate analysis for linear trend: p=0.1645). Overall prescriptions for typical antipsychotics decreased (from 27.2% in 2004 to 23.0% in 2009, p<0.0001) and prescriptions for atypical antipsychotics increased from 17.1% to 18.9% (p<0.0001). The mean DDD per treated patient increased from 80.5 to 91.2 (2004-2009; p=0.0047). Our findings imply that warnings of international drug authorities and manufacturers against adverse drug events in dementia patients receiving antipsychotics did not impact overall prescription behavior.

Keywords: Antipsychotic agents; Dementia; Germany; Health services research; Prescription trends.