OBJECTIVES: Long-term pharmacotherapy is recommended for treating schizophrenia (SZ) and bipolar I disorder (BD-I), but adverse effects of atypical antipsychotic medications, such as weight gain, contribute to suboptimal treatment adherence. The combination of olanzapine and samidorphan (OLZ/SAM) provides the established antipsychotic efficacy of olanzapine while mitigating olanzapine-associated weight gain. In real-world settings, treatment with OLZ/SAM may be associated with reductions in healthcare resource utilization (HCRU). This study examined the impact of initiating treatment with OLZ/SAM on HCRU among patients with SZ or BD-I.

METHODS: This retrospective analysis utilized administrative claims data from April 19, 2021, to December 31, 2022, from Komodo Healthcare Map. Adults with SZ or BD-I who had continuous enrollment ≥6 months before (baseline) and after (follow-up) OLZ/SAM initiation were eligible. HCRU outcomes (inpatient [IP] admissions and lengths of stay and emergency department [ED] and outpatient [OP] visits) were compared between the 6-month baseline and follow-up periods.

RESULTS: Included patients (SZ: n=855; BD-I: n=691) had a mean age of ~40 years (percent female: SZ=47%; BD-I=69%). The proportions of patients with all-cause IP admissions and ED visits significantly decreased (IP: P<0.001; ED: P<0.05) in the SZ and BD-I cohorts, as did the proportions with mental health–related IP admissions and ED visits (IP: P<0.001; ED: P<0.001), between the baseline and follow-up periods. Mean lengths of IP stay decreased in both cohorts and were significant among BD-I patients for all-cause (P=0.011) and mental health–related (P=0.007) HCRU. Proportions of patients with OP visits were similar between baseline and follow-up for both cohorts.

CONCLUSIONS: Among patients with SZ or BD-I, real-world OLZ/SAM initiation was associated with significant reductions in proportions of patients with all-cause and mental health–related hospitalizations and ED visits, indicating that OLZ/SAM may result in clinically meaningful reductions in disease burden, as evidenced by changes in inpatient care.