Risperidone: review and assessment of its role in the treatment of schizophrenia.

OBJECTIVE

To review pharmacologic, pharmacokinetic, therapeutic, and safety information for the antipsychotic agent risperidone and to evaluate its place in the treatment of schizophrenia.

DATA SOURCES

MEDLINE and Exerpta Medica databases; Janssen Pharmaceuticals; Food and Drug Administration Psychopharmacology Advisory Committee; PJB Publications; published articles and abstracts; unpublished research reports and abstracts.

STUDY SELECTION

In vivo animal studies (pharmacology); volunteer studies (pharmacokinetics); clinical case reports, open clinical studies, and controlled clinical studies (clinical efficacy and adverse effects; long-term studies; studies in special populations.

DATA EXTRACTION

Relevant data were extracted from published and unpublished source documents, evaluated, and summarized in tables for comparative review. Abstracts were used in 6 of 8 pharmacokinetic studies, 4 of 8 open clinical studies, and 2 of 9 controlled clinical studies. Use of abstracts limits the extent of data extracted.

DATA SYNTHESIS

Risperidone is an effective treatment for positive symptoms of schizophrenia and may be effective for negative symptoms. Efficacy in treatment-resistant patients is inconclusive. In patients in whom low-to-moderate dosage is effective, there should be fewer and less severe adverse effects with risperidone than with haloperidol. Optimal dosage for schizophrenia appears to be 6 mg/d. Although data are limited, risperidone may be toxic on overdose.

CONCLUSIONS

Risperidone is a useful addition to the antipsychotic drug armamentarium, but it should be viewed as an atypical antipsychotic agent. It is reasonable to consider a trial of risperidone in treatment-resistant schizophrenic patients prior to the use of clozapine and as a first-line treatment for newly diagnosed patients with schizophrenia.