Olanzapine Reduction From High Dose to Standard Dose: A Retrospective Chart Review

Purpose/background Although high-dose olanzapine might be a treatment option in patients with treatment-resistant schizophrenia, it can be reduced to the standard dose after symptoms are stabilized. We examined the rate of olanzapine reduction from high to standard dose and whether this change was successful. Methods/procedures We included patients who received high-dose olanzapine (>20 mg/d) for 4 weeks or longer at our hospital. First, we retrospectively followed the patients for 6 years and estimated the percentage of those whose olanzapine was reduced from high to standard dose. Second, we followed patients who received olanzapine reduction for 1 year and estimated the rate of success based on the study-defined criteria for unsuccessful reduction. We also explored factors associated with the dose reduction and successful results. Findings/results Among 110 patients who received high-dose olanzapine treatment, 72 had their olanzapine dose reduced to the standard dose for 6 years; the duration of high-dose olanzapine treatment was significantly and negatively associated with a reduction in olanzapine (hazard ratio, 0.98; 95% confidence interval, 0.98-0.99). Among the patients whose olanzapine was reduced, 50 achieved successful reduction for 1 year. Among the reasons for the reduction, an unknown reason was significantly associated with successful reduction (hazard ratio, 4.93; 95% confidence interval, 1.55-22.8). Implications/conclusions The findings suggest that high-dose olanzapine can be reduced to the standard dose after stabilization of symptoms in most patients with schizophrenia.