Comparative risk of death in older adults treated with antipsychotics: A population-based cohort study

Although the use of antipsychotics has been associated with an increased risk of death, data on the safety of individual substances is scarce. We thus aimed to compare the risk of death in new users of individual antipsychotics aged =>65 years and conducted a cohort study in the German Pharmacoepidemiological Research Database between 2005 and 2011. Patients were followed from initiation of treatment until death, 90 days after cohort entry, end of insurance or the end of the study period. Multivariable cox regression was used to estimate confounder adjusted hazard ratios (aHR) of death for 14 individual antipsychotics compared to risperidone. In sensitivity analyses, we also applied high-dimensional propensity score (HDPS) methods to explore possible unmeasured confounding. In a cohort of 137,713 new users of antipsychotics, a higher risk of death was found for haloperidol (aHR: 1.45; 95% confidence interval: 1.35-1.55), levomepromazine (aHR: 1.34; 1.16-1.54), zuclopenthixol (aHR: 1.32; 1.02-1.72) and to a lesser extent for melperone (aHR: 1.13; 1.07-1.19) compared to risperidone. Lower risks were observed for quetiapine, prothipendyl, olanzapine, tiapride, clozapine, perazine and flupentixol. In subgroup analyses, levomepromazine and chlorprothixene were only associated with a higher risk of death in patients aged =>80 years and with dementia. The application of HDPS methods did not substantially change the results. In conclusion, our study suggests that initiation of haloperidol, levomepromazine, zuclopenthixol and chlorprothixene treatment is associated with an increased risk of death compared to risperidone and should be avoided in older patients except in palliative care when treatment alternatives are available.