Real-world use of brexpiprazole during inpatient treatment for schizophrenia: continuation, discontinuation, and concomitant psychotropics.

Introduction: In the treatment of schizophrenia, antipsychotics used during acute inpatient care must control acute symptoms while remaining sufficiently tolerable to support treatment beyond the acute phase. Brexpiprazole, a serotonin-dopamine activity modulator may be one such option; however, its real-world use and short-term continuation in acute inpatient settings remain insufficiently characterized. Methods: We conducted a retrospective observational study of inpatients with DSM-5 schizophrenia treated with brexpiprazole at a university hospital in Japan between June 2018 and July 2024. The index date (week 0) was defined as the date of brexpiprazole initiation during the index hospitalization. The primary outcome was brexpiprazole continuation at week 8. We compared baseline demographic and treatment-related variables between the continuation and discontinuation groups and summarized reasons for discontinuation from electronic medical records. As a secondary exploratory analysis, we examined longitudinal changes in Clinical Global Impressions-Severity scale (CGI-S) and Brief Psychiatric Rating Scale (BPRS) total scores (weeks 0/4/8) in the continuation group using a linear mixed-effects model including time, concomitant psychotropic medication status, and their interaction. Results: Sixty-seven patients were included. Baseline illness severity was substantial (median CGI-S 5.0 [IQR 5.0-6.0]; mean BPRS total 58.5 ± 9.6). Concomitant psychotropic medications were common. Thirty-six patients continued brexpiprazole to week 8 (53.7%). In unadjusted exploratory comparisons, continuation was associated with the female sex (p = 0.036), lower prior chlorpromazine-equivalent dose (p = 0.015), and shorter duration of untreated psychosis (p = 0.003), with a trend toward shorter duration since onset (p = 0.073). The most frequent reason for discontinuation was adverse events (n = 10, 32.3%), most commonly akathisia (n = 6), followed by insufficient efficacy (n = 9, 29.0%) and patient preference/refusal (n = 7, 22.6%). In exploratory mixed-effects analyses within the continuation group, CGI-S and BPRS total scores decreased over time, with significant group-by-time interactions by concomitant medication status. However, between-group differences should be interpreted cautiously. Discussion: This study describes 8-week continuation and reasons for discontinuation of brexpiprazole in acute inpatient schizophrenia care. Given the retrospective single-center design and potential selection/information bias and unmeasured confounding, further studies are warranted to clarify its clinical positioning in real-world practice.