A risk-benefit assessment of risperidone in schizophrenia.

The atypical antipsychotic risperidone combines dopaminergic and serotonergic antagonism. This results in a drug that is both clinically effective, reducing positive and negative symptoms of schizophrenia, and has a low incidence of adverse effects. At a dosage of 4 to 8 mg/day, risperidone is comparable to 10 mg/day of haloperidol. This dosage has a low incidence of extrapyramidal adverse effects and is nonsedative, although it may cause orthostatic hypotension. There is no current evidence for specific biochemical and haematological abnormalities associated with risperidone. Although the clinical benefits appear to outweigh the risks, this drug continues to be a relatively expensive treatment option in the UK. There is therefore a need for a formal cost-utility assessment of risperidone and for comparisons between this drug and other atypical neuroleptics.