Study shows antipsychotic drugs increase health risks in dementia patients

By Dr. Priyom Bose, Ph.D.Reviewed by Benedette Cuffari, M.Sc.Apr 18 2024

In a recent British Medical Journal study, researchers assess the adverse effects associated with the use of antipsychotic drugs in people with dementia.

Study: Multiple adverse outcomes associated with antipsychotic use in people with dementia: population based matched cohort study. Image Credit: Fahroni / Shutterstock.com

The role of antipsychotics in dementia management

Individuals diagnosed with dementia undergo functional disability and progressive cognitive decline. Some common psychological and behavioral symptoms of dementia include anxiety, depression, apathy, aggression, delirium, irritability, and psychosis.

To manage psychological and behavioral symptoms of dementia, patients are commonly treated with antipsychotics. The United Kingdom National Institute for Health and Care Excellence currently recommends the use of antipsychotics only when non-drug interventions are ineffective in alleviating behavioral and psychological symptoms of dementia. However, there has been an increase in antipsychotic use during the recent coronavirus disease 2019 (COVID-19) pandemic, which has been attributed to lockdown measures and the unavailability of non-pharmaceutical treatments.

In the U.K., risperidone and haloperidol are the only antipsychotics that have received approval for the treatment of behavioral or psychological symptoms of dementia. In 2003, the United States Food and Drug Administration (FDA) highlighted the risks, such as stroke, transient ischaemic attack, and mortality, associated with the use of risperidone in older adults with dementia. 

Based on multiple study reports, regulatory guidelines have been formulated in the U.K., U.S., and Europe to reduce inappropriate prescriptions of antipsychotic drugs for the treatment of behavioral and psychological symptoms of dementia. To date, few studies have provided evidence of the association between antipsychotic drug prescriptions in older adults with dementia and risks of multiple diseases, such as myocardial infarction, venous thromboembolism, ventricular arrhythmia, and acute kidney injury.

About the study

The current study investigated the risk of adverse outcomes associated with antipsychotics in a large cohort of adults with dementia. Some adverse outcomes considered in this study were venous thromboembolism, stroke, heart failure, ventricular arrhythmia, fracture, myocardial infarction, pneumonia, and acute kidney injury.

Over 98% of the U.K. population is registered with National Health Service (NHS) primary care general practice. All relevant data were collected from the electronic health records held at the Clinical Practice Research Datalink (CPRD), which is associated with over 2,000 general practices. CPRD comprises the Aurum and GOLD databases, which can be considered as broadly representative of the U.K. population.

Individuals above 50 years of age and diagnosed with dementia were recruited. Importantly, none of the study participants were under antipsychotic intervention one year before their diagnosis.

The researchers utilized a matched cohort design, in which each patient who used antipsychotics after their initial dementia diagnosis was matched using the incidence density sampling method. This method considered up to 15 randomly selected patients who were diagnosed with dementia on the same date but were not prescribed antipsychotic drugs.

Antipsychotics increase the risk of adverse effects in dementia patients

Across the two cohorts, the mean age of the participants was 82.1 years. A total of 35,339 participants were prescribed an antipsychotic during the study period.

The mean number of days between the first diagnosis of dementia and the date of a first antipsychotic prescription was 693.8 and 576.6 days for Aurum and GOLD, respectively. The most commonly prescribed antipsychotics were risperidone, haloperidol, olanzapine, and quetiapine.

The current population-based study revealed that adults with dementia prescribed antipsychotics are at a greater risk of venous thromboembolism, myocardial infarction, stroke, heart failure, pneumonia, fracture, and acute kidney injury than non-users. This observation was based on analyzing 173,910 adults with dementia selected from both databases. 

The increased risk of adverse outcomes was most prevalent among current and recent users of antipsychotic drugs. After 90 days of antipsychotic use, the risk of venous thromboembolism, pneumonia, acute kidney injury, and stroke was higher than non-users. However, antipsychotic drugs did not impact the risk of ventricular arrhythmia, appendicitis, and cholecystitis.

As compared to the use of risperidone, haloperidol was significantly associated with an increased risk of pneumonia, fracture, and acute kidney injury. Although the adverse effects of haloperidol were higher than quetiapine, no significant differences were observed between risperidone and quetiapine for the risk of fracture, heart failure, and myocardial infarction. The risk of pneumonia, stroke, acute kidney injury, and venous thromboembolism was lower for quetiapine as compared to risperidone.

Conclusions 

The current study highlights how antipsychotic drugs affect older adults with dementia. The use of these drugs was associated with many serious adverse outcomes, such as stroke, acute kidney injury, pneumonia, venous thromboembolism, heart failure, and myocardial infarction.

In the future, these risks must be considered, along with cerebrovascular events and mortality, while making regulatory decisions about the use of antipsychotic drugs for the treatment of dementia in older adults.