Association between prescription of conventional or atypical antipsychotic drugs and mortality in older persons with Alzheimer's disease

Abstract

Background/aims: To evaluate whether dementia patients prescribed antipsychotic drugs have a higher mortality compared to unexposed patients, and to investigate whether there are differences in mortality associated with exposure to conventional versus atypical antipsychotic drugs.

Methods: Retrospective population cohort study with information gathered from the Italian Health Information System. All 4,369 residents of Milan (Italy) aged 60 years or older who were newly prescribed an antidementia drug (donepezil, rivastigmine or galantamine) from January 2002 to June 2008 were included. All new users of antipsychotic drugs in this cohort were categorized according to conventional (n = 156) or atypical (n = 806) drug exposure. The mortality risks of users of conventional or atypical antipsychotics compared to nonusers were evaluated with survival analysis, considering exposure to antipsychotic drugs as a time-dependent variable.

Results: Mortality was increased two- and fivefold in users of atypical and conventional antipsychotics, respectively, with respect to nonusers.

Conclusions: Dementia patients prescribed antipsychotic drugs had a higher risk of death. This risk was highest for those prescribed conventional antipsychotics. At least part of the excess mortality may be due to the underlying neuropsychiatric symptoms that prompted the use of antipsychotics rather than a direct medication effect.