title: Open study evaluating the onset of antipsychotic action of olanzapine in the treatment of patients with schizophrenia, schizophreniform or schizo-affective disorder.
abstract: OBJECTIVE This 6-week, open-label study with olanzapine was designed to determine the onset of antipsychotic action of a 10-mg/day starting dose of olanzapine, continued as a fixed dose for at least 4 weeks. METHODS A total of 306 patients experiencing an acute exacerbation of schizophrenia were prospectively followed-up. Response was defined as a 20% improvement on the Positive And Negative Syndrome Scale (PANSS) positive score, sustained until week 6. Onset of action was defined as the time point at which a 20% improvement in positive symptoms occurred and was maintained to week 6. RESULTS Significant improvements from baseline were observed throughout the study with respect to PANSS positive and PANSS total score (P<0.001). Within the first week of treatment, 20.6% of patients showed a 20% decrease in PANSS positive score, which was maintained until week 6. By weeks 2, 3 and 4 the percentage of responders had risen to 38.2, 49.7 and 52.3%, respectively. Olanzapine 10 mg/day was well tolerated, with the frequency of extrapyramidal symptoms and sexual dysfunction markedly lower following treatment than at baseline. CONCLUSION In this clinical open study, about half of the patients showed a response within 3 weeks, which is at least maintained until week 6.
authors.affiliation: Universitair Centrum St. Jozef, KUL, Kortenberg, Belgium.
authors.forename: Joseph
authors.initials: J
authors.lastname: Peuskens
authors.forename: Claudine
authors.initials: C
authors.lastname: Mertens
authors.forename: Stefan
authors.initials: S
authors.lastname: Geerts
authors.forename: Benoit
authors.initials: B
authors.lastname: Gillain
authors.forename: Betty
authors.initials: B
authors.lastname: Van Vleymen
keywords: atypical antipsychotic; olanzapine; onset of antipsychotic action; open-label; schizophrenia