Olanzapine/Samidorphan (Lybalvi) in Palliative Care: A Case Report on Medication Reconciliation, Risk-Benefit Analysis, and Psychiatric Co-Management in an Outpatient Supportive Oncology Clinic

Patients with cancer have a high rate of comorbid psychiatric disorders. While the exact prevalence of comorbid bipolar I disorder and cancer is unknown, given the worse health outcomes associated with siloed specialist care, increased knowledge of the co-management of patients with cancer and bipolar I disorder is needed in palliative care. This case highlights a need for awareness regarding the specific combination of olanzapine and samidorphan (Lybalvi), approved in 2021 for the management of bipolar I disorder. Samidorphan, an opioid antagonist, mitigates the metabolic side effects of olanzapine. Notably, patients with comorbid bipolar I disorder and cancer often have both significant anorexia and pain, making samidorphan less desirable, as, in addition to mitigating metabolic side effects, it can limit the efficacy of analgesia from opioids. A recommendation of transitioning to olanzapine only is discussed.