Switching depot antipsychotic drug responders to oral olanzapine

In an open-label study, 13 patients taking depot antipsychotic medication for greater than 3 years were switched to oral olanzapine. The first 3-month experience has been previously reported. We now describe a second 3-month experience and integrate our observations into a cumulative 6-month report. Monthly, we assessed patients using clinical ratings [Positive and Negative Syndrome Scale (PANSS), Global Assessment of Functioning (GAF), Mini-Mental State Exam (MMSE), and Clinical Global Improvement Scale (CGI)] and side effect parameters [Abnormal Involuntary Movement Scale (AIMS), Association for Methodology and Documentation in Psychiatry psychotropic side effect rating scale (AMDP-5), and weights]. Olanzapine patients showed statistically significant improvement (baseline to endpoint sixth month) in GAF (p=0.015), MMSE (p=0.022), CGI improvement, and AIMS (p=0.038). There was no statistically significant change in PANSS, CGI severity, or AMDP-5 overall side effects. Weight gain over 6 months averaged 8.9 lb. All patients completed the study. Compliance was estimated at 90%, and 81% of patients chose to continue on the oral olanzapine. One patient was hospitalized at the conclusion of the study. Our findings suggest that clinicians may consider oral olanzapine as a viable alternative to depot antipsychotic medications, balancing clinical improvement in some clinical measures with lack of improvement in other clinical measures; and balancing improvement in abnormal involuntary movements with weight gain and its sequelae.