Antipsychotic Use and Risk of Hospitalization or Death Due to Pneumonia in Persons With and Those Without Alzheimer Disease

Background The use of antipsychotic agents has been associated with increased pneumonia risk, but although people with dementia are particularly susceptible to pneumonia, only one small study has assessed the risk of pneumonia in relation to the use of antipsychotic agents among people with Alzheimer disease (AD). Methods We investigated whether the incident use of antipsychotic agents, or specific antipsychotic agents, are related to a higher risk of hospitalization or death due to pneumonia in the Medication and Alzheimer Disease (MEDALZ) cohort. The cohort includes all individuals with AD who received a clinically verified AD diagnosis in Finland in 2005 to 2011 (N = 60,584; incident pneumonia, n = 12,225). A matched comparison cohort without AD (N = 60,584; incident pneumonia, n = 6,195) was used to compare the magnitude of risk. Results were adjusted for a propensity score derived from comorbidities, concomitant medications, and sociodemographic characteristics. Sensitivity analyses with case-crossover design were conducted. Results The use of antipsychotic agents was associated with a higher risk of pneumonia (adjusted hazard ratio [HR], 2.01; 95% CI, 1.90-2.13) in the AD cohort and a somewhat higher risk in the non-AD cohort (adjusted HR, 3.43; 95% CI, 2.99-3.93). Similar results were observed with case-crossover analyses (OR, 2.02; 95% CI, 1.75-2.34 in the AD cohort and OR, 2.59; 95% CI, 1.77-3.79 in the non-AD cohort). The three most commonly used antipsychotic agents (quetiapine, risperidone, haloperidol) had similar associations with pneumonia risk. Conclusions Regardless of applied study design, treatment duration, or the choice of drug, the use of antipsychotic agents was associated with a higher risk of pneumonia. With observational data, we cannot fully rule out a shared causality between pneumonia and the use of antipsychotic agents, but the risk to benefit balance should be considered when antipsychotic agents are prescribed.