Does oral antipsychotic pre-treatment influence outcome of a switch to long-acting injectable risperidone in patients with schizophrenia?

INTRODUCTION: The objective of this open-label study was to evaluate treatment benefits of risperidone long-acting injectable (RLAI) in patients with schizophrenia following direct transition from oral risperidone (RIS) compared with transition from other oral second generation antipsychotics. METHODS: Stable in- or outpatients (n=206) receiving RIS or OQAZ (olanzapine, quetiapine, amisulpride, ziprasidone) were transitioned to RLAI for 12 weeks. The primary outcome was the between-group treatment difference in change in PANSS total score from baseline to endpoint. Secondary outcomes included health-related quality-of-life and therapeutic alliance. RESULTS: Mean between-group difference in the change in PANSS total score from baseline to endpoint was -6.1 (CI: -17.6, 5.4), suggesting greater improvement in OQAZ than RIS patients. Due to the pre-specified non-inferiority margin of 5.1, it could not be concluded that OQAZ pre-treatment results in an at least non-inferior PANSS reduction versus RIS pre-treatment. Patient satisfaction with medication and change in quality-of-life subscores showed advantages for OQAZ patients. DISCUSSION: Compared to RIS pre-treatment, clinically stable patients with schizophrenia who are pre-treated with OQAZ might draw a stronger clinical benefit from direct transition to RLAI.