A major UK study tracking more than 165,000 people living with dementia has found that risperidone raises the risk of stroke across all patients, calling into question the long-held belief that the drug may be safe for certain groups.Risperidone is a potent antipsychotic commonly given to people with dementia who develop severe agitation, particularly in care homes, when non-medicated approaches have failed.Researchers observed that the risk of stroke rose even in patients with no previous history of heart disease or stroke. The finding challenges assumptions about who can safely take the drug and has prompted fresh concerns about how risperidone, the only medication of its kind licensed for dementia, is prescribed and followed up.The findings, published in the British Journal of Psychiatry, are likely to fuel renewed discussion around current prescribing practices.What Is Risperidone?Risperidone, sold under brand names such as Risperdal and Risperdal Consta, is an atypical antipsychotic that affects brain chemicals including dopamine and serotonin. It is a prescription-only drug.Risperidone: Risk Holds Across Patient ProfilesOne of the study’s key insights was that the increased stroke risk appeared consistent across different types of patients, according to Dr Byron Creese of Brunel University of London. “We already knew risperidone was linked to stroke, but it was unclear whether some people were more vulnerable than others. We hoped to identify traits that could help doctors avoid prescribing it to higher-risk patients,” he said, as reported by Scitech Daily.About half of all people with dementia experience agitation, which can be deeply upsetting for both patients and carers. When other methods do not help, risperidone is sometimes used as a last measure. The new evidence sharpens the difficult choices doctors and families face, weighing the drug’s ability to ease extreme distress against its clearly increased stroke risk.Risperidone: Gaps In Guidance And MonitoringRisperidone, often used to manage aggressive behaviour, already carries warnings about stroke risk in older adults. However, there is still no dementia-specific guidance on how clinicians should monitor these risks. While NHS advice limits risperidone use to six weeks for severe symptoms, many patients remain on it longer, with follow-up practices differing widely.Dr Creese noted that there are no UK-licensed alternatives for such cases, making it essential that risks are clearly discussed and carefully balanced. People who have already had a stroke are naturally at higher risk of another. If a stroke occurs while taking risperidone, it may not always be possible to separate drug-related risk from underlying vulnerability. “These results give clearer information to guide decisions,” he said. “Each case should come down to what is right for the individual, through open conversations between doctors, patients, and families.”What The Data ProvesResearchers examined anonymized NHS records from 2004 to 2023, comparing patients prescribed risperidone with similar individuals who were not. Among those with a prior stroke, the annual rate per 1,000 person-years rose to 22.2 percent in people taking risperidone, compared with 17.7 percent in those who were not. In patients without a stroke history, rates were lower but still notable at 2.9 percent versus 2.2 percent. The risk was also higher during short-term use of up to 12 weeks, according to Scitech Daily.“We hope this evidence helps shape updated guidance that is more focused on individual patients and real-world risk,” Dr Creese said.