Safety of olanzapine versus conventional antipsychotics in the treatment of patients with acute schizophrenia. A naturalistic study.

Background: Conventional antipsychotics although effective in treating acute psychotic and behavioural symptoms are subject to certain limitations due to the high incidence of side effects associated, mainly extrapyramidal symptoms (EPS), and insufficient response shown in some cases. EPS are a major factor in neuroleptic non compliance and high relapse rates among patients. This study was designed to assess the safety and effectiveness of olanzapine compared to typical antipsychotics drugs in the treatment of schizophrenic inpatients at acute psychiatric in-patient units.

Method: Data from 904 patients schizophrenic patients (F20 of ICD10, WHO) were collected in this prospective, comparative, non-randomized, open and observational study. Patients were followed during their entire hospital stay. Safety was assessed through the collection of spontaneous adverse events and a specific extrapyramidal symptoms questionnaire (EPS). Clinical status was measured through the Brief Psychiatric Rating Scale (BPRS), Clinical Global Impression of Severity (CGI-S), Patient Global Impression of Improvement (PGI) and the Nursing Observational Scale for In-patient Evaluation (NOSIE).

Results: A total of 483 patients received olanzapine (olanzapine group, OG), and 421 received typical antipsychotics (control group, CG). Treatment emergent EPS, or worsening of previous EPS were statistically significantly higher in the CG (P=0.001). Responder rate was statistically greater in the OG (P<0.001). Mean change in BPRS-total, BPRS-negative, BPRS-agitation subscales and PGI was significantly higher in the OG (P<0.001). Mean decrease in CGI, BPRS positive and BPRS depression sub-scales was also significantly lower (P< or =0.05). Mean change in the NOSIE scale was similar between both groups.

Conclusion: Olanzapine has been shown to be better tolerated in comparison with conventional antipsychotics in a large unselected sample of acutely psychotic schizophrenic in-patients. Its effectiveness may be greater than that of conventional antipsychotics.