Antipsychotic use is widely prescribed to people with dementia for the treatment of behavioural and psychological symptoms (such as apathy, depression, aggression, anxiety, irritability, delirium and psychosis) despite concerns about their use. Previous studies have reported increased risks for stroke and mortality, and although other adverse side effects have been investigated, results are more limited and less conclusive in people with dementia. In a new study published in the British Medical Journal (BMJ), a team of researchers led by Dr Pearl L H Mok from the University of Manchester (UK) investigated the risks of multiple adverse outcomes (i.e. stroke, venous thromboembolism, myocardial infarction, heart failure, ventricular arrhythmia, fracture, pneumonia, and acute kidney injury) potentially associated with antipsychotic use in people with dementia.
A total of 35,339 older adults, who were aged 50 years or over at the time of the dementia diagnosis and were not prescribed any antipsychotic in the year before their dementia diagnosis, were prescribed an antipsychotic on or after the date of their dementia diagnosis. Each of them was then matched with up to 15 randomly selected individuals with a dementia diagnosis who never became users of antipsychotics. The most prescribed antipsychotics were risperidone, quetiapine, haloperidol, and olanzapine. Data collected showed that antipsychotic users were more likely than their matched non-users to have a history of mental illness. Moreover, in the two years after initiation of antipsychotics, and compared with non-use, antipsychotics were associated with increased risks for all outcomes analysed, except for ventricular arrhythmia.
In addition, and for almost all the outcomes, risks were highest during the first week of antipsychotic treatment. The study findings show a wide range of adverse events in a large population of people with dementia with the use of antipsychotics. However, this is an observational study and no firm conclusions can be drawn. Further research is therefore needed and any potential benefits of antipsychotic treatment need to be weighed against risk of serious harm.
https://www.bmj.com/content/bmj/385/bmj-2023-076268.full.pdf
