A large British study of more than 165,000 people with dementia found that the drug risperidone was associated with an increased risk of stroke in all patient groups. This finding challenges previous assumptions that certain patients may be safer candidates for medication. Instead, the researchers found no clearly “safe” group.
Risperidone is a powerful antipsychotic drug that is often prescribed to dementia patients who experience severe agitation and aggressive behavior. It is commonly used in nursing homes when non-drug approaches cannot control distressing symptoms.
However, this study showed that people with dementia who take risperidone have an increased risk of stroke, even if they do not have a history of heart disease or stroke. This raises new concerns about how drugs are prescribed and monitored. Risperidone is currently the only drug approved for use in people with dementia in the UK.
The result is British Journal of Psychiatry And that could lead to calls for change in clinical practice.
Researchers find stroke risk is consistent across patient groups
One of the most striking findings was how evenly the risk of stroke appeared among different types of patients.
“We knew that risperidone caused strokes, but we didn’t know whether some groups of people were at higher risk than others. We thought that if we could identify the characteristics that put people at greater risk, doctors could avoid prescribing it to patients with those characteristics,” said Dr. Byron Creese from Brunel University London.
Approximately half of people with dementia experience agitation, which can cause significant distress to both patients and caregivers. If behavioral therapy and other nondrug strategies fail, your doctor may prescribe risperidone as a last resort.
These results highlight the difficult decisions faced by physicians and families. They must balance the drug’s ability to calm intense agitation with the potential for serious side effects, such as stroke.
Limited alternatives and inconsistent monitoring
Risperidone, which is often used to reduce aggression and hyperexcitement, is already known to increase the risk of stroke in older people. Despite this, there is still no dementia-specific guidance on how doctors should monitor patients for these risks.
Current NHS guidance recommends limiting treatment to six weeks when using risperidone for severe symptoms. In reality, many patients continue to take medications for long periods of time. How monitoring is conducted may also vary by region within the country.
Dr Cleese says there are currently no alternative medicines approved in the UK to treat severe agitation in people with dementia. For this reason, doctors must carefully explain the risks and benefits before prescribing.
People who have already had a stroke are naturally more likely to have one again. If a stroke occurs after you start taking risperidone, the drug is not necessarily the only cause. Doctors usually prescribe the drug only if other options have not worked.
“These findings provide clearer information about who is most at risk and help everyone make more informed choices. All decisions should be made based on what is right for each person through honest conversations between doctors, patients and families,” Dr. Creese said.
How researchers studied stroke risk
The research team looked at anonymized NHS health records collected between 2004 and 2023 and compared people with dementia who were prescribed risperidone to similar patients who were not taking risperidone.
Among people who had previously had a stroke, the annual incidence per 1000 person-years of those taking risperidone rose to 22.2%. In contrast, the proportion of those not using the drug was 17.7%.
For patients without a previous stroke, the overall risk was lower, but still significant. The stroke rate for people taking risperidone reached 2.9%, while the stroke rate for people not taking risperidone reached 2.2%. Researchers also found that patients who used the drug for a short period of time (12 weeks) had an increased risk of stroke.
“We hope these data will be used for updated guidance that is more person-centered and based on specific patient characteristics,” Dr. Creese said.
