O-72: The risk of head injuries and traumatic brain injuries associated with antipsychotic use among community-dwellers with Alzheimer's disease

摘要

Introduction: Antipsychotic use is associated with increased risk of falls in older population. However, there are no previous studies concerning antipsychotic use and risk of head injuries among persons with Alzheimer's disease (AD). We studied the association between antipsychotic use and head injuries among community-dwelling persons with AD. Methods: A cohort study comparing antipsychotic users with matched nonusers in the MEDALZ cohort that includes all Finnish community-dwellers who received clinically verified AD diagnosis in 2005-2011. Incident antipsychotic users were identified with 1-year washout period using Prescription Register. The number of matched user-nonuser pairs was 21,795. Data on head injuries were extracted from Hospital Discharge and Causes of Death Registers. The association of antipsychotic use with head injuries and traumatic brain injuries (TBIs) were investigated with inverse probability of treatment (IPT) weighted Cox proportional hazard models. Results: Antipsychotic use was associated with increased risk of head injuries [event rate per 100 person-years 1.65 (95% confidence interval, CI 1.50-1.81) for users and 1.26 (1.16-1.37) for nonusers, IPT-weighted hazard ratio HR (95% CI) 1.29 (1.14-1.47)] and TBIs [event rate per 100 person-years 0.90 (0.79-1.02) for users and 0.72 (0.65-0.81) for nonusers, IPT-weighted HR 1.22 (1.03-1.45). Queti-apine users had higher risk of TBIs [IPT-weighted HR 1.60 (95% CI 1.15-2.22)] in comparison to risperidone users. Conclusions: These findings imply that in addition to previously reported adverse events and effects, antipsychotic use may increase the risk of head injuries and TBIs in persons with AD. Therefore, their use should be restricted to most difficult neuropsychiatric symptoms.