Risperidone

How it works

It is a potent antagonist at dopamine D2 and serotonin 5-HT2A receptors, with additional alpha-adrenergic and histaminergic blockade, reducing positive psychotic symptoms while raising prolactin.

Prescribing in practice

• It increases the risk of stroke and death when used for behavioural and psychological symptoms in elderly people with dementia, so such use must be short-term, justified and reviewed.
• It commonly raises prolactin, which can cause galactorrhoea, sexual dysfunction and menstrual disturbance, and is dose-dependently associated with extrapyramidal side effects.
• Postural hypotension can occur on initiation and dose titration, particularly in the elderly.

Monitoring

Monitor weight, fasting glucose or HbA1c, lipids, blood pressure, prolactin-related symptoms and emergence of extrapyramidal effects at baseline and regularly.

Counselling the patient

• Report breast changes, milk production, sexual or menstrual problems, or muscle stiffness and abnormal movements.
• Stand up slowly when starting treatment to reduce dizziness.
• Attend regular physical-health checks and do not stop the medicine abruptly without advice.

Evidence & guidelines

NICE lists risperidone among first-line antipsychotic options for schizophrenia and bipolar mania, with explicit caution about stroke risk in dementia.