Risperidone: neurochemical, pharmacologic and clinical properties of a new antipsychotic drug.

Risperidone, a novel antipsychotic with high binding affinity for serotonin 5-HT2 and a lesser affinity for dopamine D2 receptors, is described and clinical studies are reviewed. In two large-scale trials in North America and Europe, risperidone 6 mg and 4 mg to 8 mg/day compared favourably with haloperidol 20 mg or 10 mg/day in controlling the positive symptoms of schizophrenia. In the North American trial, risperidone produced a significant improvement in negative symptoms; no comparable improvement was reported among haloperidol-treated patients. Risperidone would, thus, appear to offer a potential advantage over other neuroleptics, although the place of this new compound in the pharmacological armamentarium of schizophrenia must be clarified in clinical practice.