Comparison of Risperidone and Olanzapine in Bipolar and Schizoaffective Disorders.

OBJECTIVE

To compare risperidone and olanzapine for efficacy, tolerability, need for concomitant mood stabilizers, and cost of treatment in bipolar and schizoaffective disorders. METHOD: We conducted a retrospective chart review of 36 consecutive outpatients with DSM-IV bipolar or schizoaffective disorder seen in 3 settings who received risperidone or olanzapine for at least 1 month between May and August 1997.

RESULTS

The mean +/- SD doses were 3.7 +/- 3.5 mg/day of risperidone and 12.0 +/- 5.4 mg/day of olanzapine. Between-treatment differences in patient characteristics, psychiatric history, Clinical Global Impressions scale ratings, and duration of treatment were not significant. Similar proportions of patients in the 2 groups reported side effects, including extrapyramidal symptoms, akathisia, tardive dyskinesia, and precipitation of mania by the respective drug. Patients in the olanzapine group received a significantly higher dose of concomitant lithium than those receiving risperidone (mean daily lithium doses: risperidone group, 750 +/- 150 mg; olanzapine group, 1211 +/- 186 mg; p =.006). The total daily acquisition cost per patient was $11.84 for olanzapine versus $5.81 for risperidone.

CONCLUSION

Olanzapine and risperidone were equally efficacious and safe in the treatment of patients with bipolar or schizoaffective disorder, but treatment costs and dose of concomitant lithium were lower in risperidone-treated patients.