News Brief: New Study: More Evidence of the Risks of Antipsychotic Use in People With Dementia

A large observational study from the United Kingdom adds to the evidence that antipsychotic use in people with dementia is associated with markedly increased risks of serious, sometimes deadly, adverse reactions.[1] The medications studied included first-generation (typical) and newer (atypical) antipsychotics, including haloperidol (HALDOL), risperidone (RISPERDAL) and quetiapine (SEROQUEL).

The 2024 study, published in the BMJ, analyzed U.K. electronic health records from 1998 through 2018 pertaining to people with a first diagnosis of dementia who were at least 50 years old (mean age 82 years) and had not used antipsychotics in the prior year. The U.K. maintains high-quality health records for most of their population.

The study identified 173,910 adults with dementia, about 35,300 of whom were prescribed antipsychotics and about 138,600 of whom were not treated with such drugs. Each person prescribed antipsychotics was matched, by date of first dementia diagnosis, to up to 15 people not treated with antipsychotics. Outcome comparisons between these two groups were statistically adjusted for differences that might otherwise be explained by personal characteristics (for example, sex, ethnicity or regional poverty), lifestyle (for example, tobacco or alcohol use), comorbidities (for example, diabetes, arthritis or cancer) and other prescriptions (for example, anticoagulants or antidepressants).

The adverse outcomes that were studied included stroke, venous thromboembolism (blood clots), myocardial infarction (heart attack), heart failure, ventricular arrhythmia, bone fracture, pneumonia and acute kidney injury. Antipsychotic prescriptions were associated with increased risks of all the main adverse outcomes except ventricular arrythmia. For example, the pneumonia risk associated with a current antipsychotic prescription was calculated as 2.19 times the risk absent such drugs, acute kidney injury risk was similarly elevated by 1.72 times, fracture risk by 1.43 times and myocardial infarction by 1.28 times. These adverse outcomes were largest if the follow-up period was less than 30 days after starting antipsychotics, although many of these adverse effects were still evident up to two years later, some even after such drugs had been discontinued. Typical and atypical antipsychotics had a similar profile of adverse outcomes, although the typical drugs were associated with a slightly higher risk of stroke, heart failure, pneumonia and acute kidney injury.

Since 2004, Public Citizen’s Health Research Group has recommended against antipsychotic use in people with dementia.[2],[3] The new study reinforces these long-standing concerns.
 

References

[1] Mok PLH, Carr MJ, Guthrie B, et al. Multiple adverse outcomes associated with antipsychotic use in people with dementia: population based matched cohort study. BMJ. 2024 Apr 17;385:e076268.

[2] Worst Pills Best Pills News. Antipsychotic drugs: dangerously overused. November 5, 2004. https://www.worstpills.org/chapters/view/21. Accessed April 24, 2024.

[3] Worst Pills Best Pills News. Brexpiprazole: Do Not Use for agitation due to Alzheimer’s dementia. October 2023. https://www.worstpills.org/newsletters/view/1559. Accessed April 24, 2024.