Olanzapine for the treatment of chronic refractory schizophrenia: a 12-month follow-up naturalistic study

OBJECTIVE: The aim of this study is to provide long-term data on the effectiveness and safety of olanzapine in a group of patients with severe refractory schizophrenia. GENERAL METHODS: Twenty patients who had previously received treatment with typical antipsychotic agents and who met the DSM-IV criteria of schizophrenia and refractoriness to treatment were evaluated in a 1-year prospective study after switching to olanzapine. The Positive and Negative Symptoms Scale (PANSS) and the Brief Psychiatric Rating Scale (BPRS) were used to measure effectiveness. The extrapyramidal symptoms were also recorded. Serial laboratory tests, electrocardiograms and body weight measurements were also performed. Longitudinal statistical analyses were performed on the global changes in the scores of the scales by means of a repeated measures analysis of variance. RESULTS: Significant reductions in the global scores from baseline in the PANSS, as well as in the BPRS, were observed. Furthermore, these reductions were also significant when considered only from Week 12. Olanzapine was, in general, well tolerated; a weight gain was observed between baseline and Month 4.5, but, interestingly, it decreased again from this time point to Month 12. CONCLUSION: Olanzapine was shown to be a suitable treatment for refractory schizophrenia in this series of seriously ill patients. Although most of the effects were observed before Week 12, improvement persisted after 1 year. Weight gain stopped or even regressed when the treatment was prolonged. Large controlled clinical trials to define the role of atypical antipsychotics for the management of treatment-refractory schizophrenia are necessary.