This information is for people who have dementia, or their carers. It tells you about risperidone, a treatment used for dementia. It is based on the best and most up-to-date research.
Does it work?
Risperidone can help some people with dementia who have symptoms such as aggression and agitation (getting upset easily). But older people who take this drug for dementia have an increased risk of having a stroke. Risperidone is no longer considered a safe treatment for older people.
What is it?
Risperidone is an antipsychotic drug. It is normally used to treat people with serious mental health problems like schizophrenia. It is a newer type of antipsychotic drug and may have fewer side effects than older antipsychotic drugs.
Risperidone has sometimes been given to people in the later stages of dementia.
But the Committee on Safety of Medicines (CSM) says risperidone should no longer be used to treat older people with Alzheimer's disease or other types of dementia, because the drug increases their risk of having a stroke.  The CSM is an independent group of experts that advises the British government on drug safety.
Some older people with dementia have times when they are very disturbed and out of touch with reality. Doctors call this condition acute psychosis. The CSM says these people can take risperidone but only for a short time and only when being treated by a specialist.
If you are looking after someone with Alzheimer's or another form of dementia and they are taking risperidone, you should arrange for them to see their doctor as soon as possible. They should not stop taking the drug without first seeing a doctor.
The CSM's advice about risperidone is only for people with dementia. But doctors are also advised to be cautious when giving risperidone to people who have had a stroke or a mini-stroke, or have high blood pressure or diabetes.
How can it help?
Someone who takes risperidone is likely to:  
Become less aggressive (they're less likely to scream, curse, or lash out at other people)
Feel less anxious
Have fewer moments when they imagine things are happening when they're not (delusions).
But risperidone has serious side effects and is no longer considered safe for older people with dementia.
How does it work?
Risperidone works by blocking the activity of two chemicals in the brain, serotonin and dopamine. These chemicals help electrical signals travel between brain cells. They are known as neurotransmitters.
Symptoms such as delusions, aggression, and violence may happen because there is too much serotonin or dopamine in the brain. Stopping these chemicals working might help these symptoms.
Can it be harmful?
Antipsychotics can have dangerous side effects when they're used to treat older people with dementia. People taking these drugs run a higher risk of serious heart problems or a stroke. Antipsychotics can also cause unpleasant but less dangerous problems, like muscle twitches.