Higher Stroke Risk Linked to Common Dementia Drug Risperidone, UK Study Finds
A large UK study of more than 165,000 people with dementia has found that the antipsychotic medication risperidone is associated with an increased risk of stroke in all patient groups. The results challenge earlier assumptions that some groups of patients might be relatively safer candidates for the drug, suggesting there is no clearly “low-risk” population for its use.
Key Points at a Glance
- Risperidone, widely used to manage agitation in dementia, is linked to a higher risk of stroke, even in patients without a previous history of stroke or heart disease.
- No subgroup of patients was identified as fully protected from this increased risk.
- NHS guidelines currently advise restricting risperidone use to six weeks, but in practice, many patients take it for longer, often without consistent review.
- No alternative licensed medications exist in the UK specifically for severe agitation in dementia, making careful evaluation of risks and benefits essential.
What Is Risperidone’s Role in Dementia Care?
Risperidone is a powerful antipsychotic drug frequently prescribed to people with dementia who experience serious agitation, aggression, or distressing behavioral symptoms. It is particularly common in care home settings, where staff may turn to medication when non-pharmacological strategies fail to control severe agitation.
Around half of all individuals living with dementia are thought to experience agitation at some point, which can be highly distressing both for them and for their families or carers. In these situations, risperidone is sometimes used to reduce aggressive or disruptive behavior and improve safety.
Stroke Risk Seen in All Dementia Patient Groups
The new research, published in the British Journal of Psychiatry, found that the elevated stroke risk linked to risperidone was apparent across all categories of dementia patients studied.
Dr. Byron Creese of Brunel University London noted that while the stroke risk associated with risperidone was already known, it had been unclear whether certain types of patients might be more vulnerable than others. The study set out to identify specific characteristics that might signal higher or lower risk, but the results suggest the risk is broadly shared.
Detailed Findings on Stroke Risk
Researchers examined anonymized NHS health records from 2004 to 2023, comparing outcomes for dementia patients prescribed risperidone with similar patients who did not receive the drug.
Key findings include:
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Patients with previous stroke:
- Those taking risperidone experienced an annual stroke rate of 22.2 per 1,000 person-years, compared with 17.7 per 1,000 person-years among those not on the drug.
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Patients with no prior stroke:
- For individuals without a stroke history, the stroke rate was 2.9 per 1,000 person-years for risperidone users, versus 2.2 per 1,000 person-years in non-users.
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Short-term use:
- The study also noted that a higher stroke risk was evident even in those who took the medication for relatively short periods, such as 12 weeks, indicating that risk is not limited to long-term treatment.
Overall, the data suggest that the use of risperidone is associated with a consistently higher stroke rate, regardless of previous cardiovascular history or treatment duration.
What This Means for Doctors, Patients, and Families
These findings underline the complex decisions faced by clinicians, patients, and families when considering risperidone for severe agitation in dementia. The drug can sometimes provide meaningful relief from intense behavioral symptoms, potentially improving quality of life and safety. However, this benefit must be weighed against the serious risk of stroke.
Current NHS recommendations advise:
- Using risperidone only for severe agitation or aggression in dementia.
- Limiting treatment to six weeks whenever possible.
- Reviewing patients regularly to decide whether the medication can be reduced or stopped.
In reality, the study suggests that many people remain on risperidone for much longer than six weeks, and the degree of ongoing monitoring is variable.
Dr. Creese highlighted the need for updated, more individualized guidance that takes account of each person’s health status, preferences, and circumstances. He stressed that decisions about starting or continuing risperidone should be made through open, honest discussion among doctors, patients, and families, asking what is truly in the best interest of the individual.
Source
- Dementia drug raises stroke risk — even in ‘low-risk’ patients, UK study shows, Brunel University London.
