Objective: Patients with Alzheimer disease (AD) show a high incidence of behavioural and psychological symptoms of dementia, which often lead to the prescription of antipsychotics. Our study sought to assess the impact of the initiation of memantine or cholinesterase inhibitors (ChEIs) on the use of antipsychotics.
Method: A retrospective cohort study was conducted using data from the Quebec provincial health plan database. Patients included in our study had received a diagnosis of AD and were initial users of memantine or ChEIs. The proportion of patients who used antipsychotics was estimated using prescription data dating back to 1 year before and to 1 year after the first prescription of memantine or ChEIs. The difference between the slopes corresponding to the periods pre- and postmemantine or ChEIs was analyzed using an interrupted time series design.
Results: The percentage of antipsychotic users increased by 118.3% before and by 68.3% after initiation of a ChEI, and increased by 68.6% before and by 7.0% after initiation of memantine. Antipsychotic trends pre- and post-ChEI initiation were not statistically different (P = 0.89), while a statistical difference was observed when comparing the antipsychotic trends pre- and postmemantine initiation (P < 0.001).
Conclusions: The initiation of memantine, unlike ChEIs, has a notable stabilization effect on the prescription of antipsychotics in patients with AD.