Adverse events in the elderly population of Manitoba treated with antipsychotic pharmacotherapy

Abstract

The safety of antipsychotic use in elderly persons has recently been questioned. The incidence of adverse events (AEs) (extrapyramidal syndromes (EPS), cerebrovascular and cardiac events, and all-cause mortality) in the elderly users of first-generation antipsychotics (FGAs) and second-generation antipsychotics (SGAs) was compared. Risks of AEs in antipsychotic-exposed persons and non-exposed individuals were also assessed. A population-based retrospective cohort study was conducted in the elderly Manitoba residents who received their first antipsychotic medication between April 1, 2000 and March 31, 2007. Cox proportional hazards models were built to compare risks of AEs in FGA and SGA users, as well as in non-exposed subjects. SGAs were associated with a lower risk of all-cause mortality (adjusted HR 0.683, 95% CI 0.577–0.809) and a higher risk of myocardial infarction (1.614 [1.024–2.543]) compared to FGAs. No significant differences between FGAs and SGAs were found for cerebrovascular events, cardiac arrhythmia and congestive heart failure (CHF) but a higher incidence of EPS was observed for FGAs compared to risperidone. Both FGA and SGA users were at a higher risk of cerebrovascular events (FGAs 1.415 [1.114–1.797]; SGAs 1.611 [1.388–1.869]) and CHF (FGAs 1.228 [0.893–1.689]; SGAs 1.242 [1.003–1.536]) compared to non-exposed subjects. Only FGA-users were at a higher risk of death compared to non-exposed subjects (FGAs 1.387 [1.065–1.805]; SGAs 0.824 [0.708–0.959]). Both FGA and risperidone use were associated with a higher risk of EPS (FGAs 3.503 [2.271–5.403]; risperidone 1.733 [1.214–2.472]). Both classes of antipsychotics might lead to potentially life-threatening AEs. Neither FGAs nor SGAs seem to have a superior overall safety profile. Antipsychotic pharmacotherapy should be prescribed in elderly persons after careful consideration of all risks and benefits.