Risperidone as an adjunct to clozapine therapy in chronic schizophrenics

J Clin Psychiatry. 1996 Sep;57(9):395-7.


Background: Some treatment-resistant schizophrenic patients improve enough to remain out of the hospital but continue to have significant positive or negative symptoms.

Method: The goal of this study was to assess the safety and potential efficacy of risperidone as an adjunct for schizophrenic patients treated with clozapine. In an open 4-week trial involving 12 DSM-III-R-diagnosed patients, the addition of risperidone to clozapine was well tolerated and did not affect serum clozapine concentrations significantly.

Results: Total Brief Psychiatric Rating Scale (BPRS) scores and subscales measuring positive symptoms, negative symptoms, and depressive symptoms were significantly reduced from baseline. Ten of 12 participants had a 20% or greater reduction in the total BPRS score.

Conclusion: In this open trial, the addition of risperidone to clozapine was well tolerated and produced significant reduction of symptoms, suggesting that this may be a useful clinical approach. Because this was an open trial, the improvement we observed must be replicated in a controlled trial.

Publication types

  • Clinical Trial

MeSH terms

  • Adult
  • Ambulatory Care
  • Antipsychotic Agents / pharmacokinetics
  • Antipsychotic Agents / therapeutic use*
  • Chronic Disease
  • Clozapine / therapeutic use*
  • Drug Interactions
  • Drug Therapy, Combination
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Psychiatric Status Rating Scales / statistics & numerical data
  • Risperidone / pharmacokinetics
  • Risperidone / therapeutic use*
  • Schizophrenia / diagnosis
  • Schizophrenia / drug therapy*
  • Schizophrenic Psychology
  • Treatment Outcome


  • Antipsychotic Agents
  • Clozapine
  • Risperidone