Risperidone as an adjunct to clozapine therapy in chronic schizophrenics.

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.