Amisulpride Augmentation in Schizophrenia Patients with Poor Response to Olanzapine: A 4-week, Randomized, Rater-Blind, Controlled, Pilot Study

Objective: The purpose of this study was to compare the efficacy and tolerability of continued olanzapine (OLA) versus amisulpride (AMI) augmentation in schizophrenic patients with poor response to OLA monotherapy. Methods: The present 4-week, randomized, rater-blinded study included 25 patients with schizophrenia who were partially or completely unresponsive to treatment with OLA monotherapy. Eligible subjects were randomly assigned at a 1:1 ratio to continuation of OLA monotherapy (OLA group) or OLA with AMI augmentation (AMI group). Efficacy was primarily evaluated using the Positive and Negative Syndrome Scale (PANSS) at baseline and at 1, 2, and 4 weeks. Results: The changes in PANSS total score and PANSS-positive subscale score were significantly different (p ＜ 0.05) between the OLA and AMI groups. The differences between the two groups in PANSS-negative subscale, PANSS-general subscale, Brief Psychiatric Rating Scale, and Clinical Global Impression-Severity (CGI-S) scale scores were not statistically significant. Conclusion: AMI augmentation could be an effective strategy for patients with schizophrenia who show inadequate early response to OLA monotherapy.