Background: When patients with schizophrenia fail to respond to an atypical antipsychotic, they are sometimes switched to another atypical compound. However, the benefits of such a switch have not been adequately studied. We present an open-label prospective 14-week trial with olanzapine in patients with schizophrenia and schizoaffective disorder whose treatment resistance to clozapine, olanzapine, risperidone, and haloperidol had been determined prospectively.
Method: The subjects were 45 inpatients with DSM-IV schizophrenia or schizoaffective disorder who failed to respond to treatment during a 14-week double-blind trial comparing clozapine, olanzapine, risperidone, and haloperidol. The patients had been selected for participation in the double-blind trial on the basis of a history of suboptimal response to previous treatment. Inclusion criteria for the present study were (1) completion of at least 8 weeks of the 14-week double-blind trial, (2) treatment resistance to 1 of the 4 compounds tested as evidenced by a decrease in total PANSS score of less than 20%, and (3) total PANSS score > or = 60. Subjects were cross-titrated from the previous double-blind treatment to open-label olanzapine, 10 to 40 mg/day, and were treated for 14 weeks without concomitant psychotropic medication. Patients were evaluated weekly with the Positive and Negative Syndrome Scale (PANSS), Clinical Global Impressions scale, and Extrapyramidal Symptom Rating Scale.
Results: Open-label olanzapine treatment yielded no significant change in PANSS total, positive subscale, or negative subscale scores. There was a significant improvement for the PANSS cognitive factor (mean +/- SD change = 0.92 +/- 2.27; F = 7.5, df = 1,44; p <.009) and a marginally significant worsening for the excitement factor (mean change = -1.36 +/- 4.64; F = 4.0, df = 1,44; p < .053). Nine percent of patients (N = 4) were classified as responders using the Kane et al. criteria. The worsening in the PANSS excitement factor was significantly associated with the length of illness (t = -2.10, df = 44, p < .04). There was a nonsignificant decrease in extrapyramidal side effects and a significant increase in weight (mean increase = 3.5 +/- 6.2 kg [7.8 +/- 13.8 lb]; F = 5.29, df = 1,42; p <.0005).
Conclusion: Our results indicate that in patients with treatment-resistant schizophrenia, a switch to olanzapine after treatment failure with an atypical agent or haloperidol may not reduce psychopathology in general, but may improve symptoms related to cognitive function.