Antipsychotics and mortality in Parkinsonism

Background — The use of antipsychotic medications is associated with an increased risk of death in older adults with dementia. The risk of death in patients with preexisting parkinsonism who receive antipsychotic drugs is not known.

Methods — Using a nested case-control design, we examined the risk of death within 30 days of newly starting antipsychotic medications among people with Parkinsonism aged 70 years and older in Ontario, Canada. Data were obtained from Ontario's healthcare administrative databases.

Results — Among 5,391 individuals with parkinsonism who died during the study period (2002-2008) and a matched comparison group of 25,937 who were still alive, individuals exposed to atypical antipsychotic drugs had a higher risk of death (unadjusted odds ratio [OR] = 2.8, 95% CI: 2.1-3.8, adjusted OR: 2.0, 95% CI: 1.4-2.7). Results were similar for quetiapine use compared with no antipsychotic use (unadjusted OR: 2.5, 95% CI: 1.6-4.0, adjusted OR = 1.8, 95% CI: 1.1-3.0). Typical antipsychotics were associated with an increased odds of death compared with atypical antipsychotics (unadjusted OR = 2.4, 95% CI 1.1-5.2, adjusted OR = 2.4, 95% CI: 1.1-5.7).

Conclusions — Individuals with parkinsonism who are newly prescribed antipsychotic medications have a higher risk of death within 30 days than those who do not start these medications. Although it is not possible to establish causality, the results suggest an increased risk. It is important to be vigilant for accompanying serious medical conditions that may increase mortality in individuals requiring treatment with antipsychotics and to consider alternative approaches to treating psychosis, agitation, and aggression in this population.