Antipsychotic drug use among nursing home residents taking rivastigmine

Objective: To evaluate whether or not rivastigmine use is associated with a decrease in the initiation of antipsychotic drug therapy among nursing home residents in the United States. Methods: A retrospective analysis was performed using Minimum Data Set data and physician order files for newly admitted residents of 452 US nursing facilities from 2000 through 2002. The rivastigmine group included those who were diagnosed with Alzheimers disease (AD) and began rivastigmine treatment within 30 days of diagnosis. Patients were required to be on treatment for a minimum of 30 days. The control group included those who were diagnosed with AD, but did not receive a cholinesterase inhibitor. All subjects were antipsychotic drug-naive within 30 days of baseline (initiation of rivastigmine or initial AD diagnosis). A Cox proportional hazards model was used to estimate predicted risk of antipsychotic drug use. Results: This study included 845 patients in the rivastigmine group and 517 patients in the control group. The rivastigmine group had fewer female patients, was younger, and had more verbal distress, sleep issues, sadness, loss of interest, and behavioral symptoms at baseline compared with the control group (P < .01). Overall initiation of antipsychotics was lower in the rivastigmine group (8.6%) compared with the control group (17.0%). Patients in the control group were almost 2 times more likely (relative risk = 1.86; P < .001) to take antipsychotics compared with patients taking rivastigmine, after adjusting for demographic covariates and mental health conditions or behavioral symptoms at baseline. Patients with baseline mental health conditions or behavioral symptoms were more likely to start antipsychotics than those without such conditions (P < .001). Conclusions: Study results suggest that nursing home residents with Alzheimers disease treated with rivastigmine have a reduced risk of initiating therapy with an antipsychotic drug compared with residents who do not receive cholinesterase inhibitor treatment.