Repeated subcutaneous esketamine administration for depressive symptoms and pain relief in a terminally ill cancer patient: A case report

Background: Depressive disorders are common among cancer patients. Ketamine can quickly relieve depression, and its subcutaneous administration appears to be as effective as and probably safer than its standard intravenous administration. Herein, we report a case verifying the antidepressant effect of a subcutaneous esketamine formulation. Case presentation: A 65-year-old male with metastatic abdominal tumor reported sadness, weight loss, fatigue, hopelessness, insomnia, inattention, and reduced motivation. His scores on the visual analogical scale for pain and Montgomery-Asberg depression rating scale were 8/10 and 30/60, respectively. Possible courses of action: Monoaminergic antidepressants are effective, but their response is slow for end-of-life care. Formulation of a plan: Esketamine was preferred because it possibly contributes to pain relief. It can repeatedly be infused intravenously, but was subcutaneously administered twice a week for safety reasons. Outcome: The patient showed continuous mood improvement, achieving depression remission on day 7. Pain relief was observed but without stability. His vital signs remained stable, and he remained calm, without major complaints. Lessons from the case: Repeated subcutaneous esketamine injections are possibly safe and effective in pain and depression relief in palliative care cancer patients. View on research problems, objectives, or questions generated by the case: Placebo-controlled studies with similar cases are needed to establish efficacy and safety.