Risperidone: a review of its use in the management of the behavioural and psychological symptoms of dementia

Risperidone is a benzisoxazole derivative which has proven efficacy against the positive and negative symptoms of schizophrenia. It has more recently been investigated and shown efficacy as a treatment for the behavioural and psychological symptoms associated with dementia in the elderly. Risperidone has pharmacological properties resembling those of the atypical antipsychotic clozapine and an improved tolerability profile compared with the conventional antipsychotic haloperidol. Risperidone has antagonistic activity primarily at serotonin 5-HT2A and dopamine D2 receptors. In the first 2 large, well controlled trials of an antipsychotic agent used in the treatment of elderly patients with Alzheimer's dementia, vascular dementia or mixed dementia, risperidone 1 mg/day was at least as effective as haloperidol and superior to placebo, as assessed by the rating scales for global behaviour, aggression and psychosis. In extension phases of the 2 trials, clinical benefits were maintained for treatment periods of up to 1 year, with an incidence rate of tardive dyskinesia (2.6%) one-tenth of that seen with conventional antipsychotics. Risperidone, administered at a low dosage of 1 mg/day was associated with fewer extrapyramidal symptoms compared with haloperidol in elderly patients. Risperidone was well tolerated with no clinically relevant abnormalities in laboratory tests, vital signs or electrocardiogram results. Conclusion: The efficacy of risperidone has been demonstrated in the treatment of the behavioural and psychological symptoms associated with dementia in the elderly. Preliminary results from 1-year extension studies confirm the favourable efficacy and tolerability profile of risperidone 1 mg/day. Although head to head studies with other atypical antipsychotic agents are required and the long term use of the drug requires clarification, risperidone represents a generally well tolerated and effective treatment in the management of dementia-associated behavioural and psychological symptoms in the elderly.