Successful pain control with morphine combined with continuous intravenous infusion of ketamine and amitriptyline for an infant with neuroblastoma

Abstract

We report a case of primary left-sided adrenal neuroblastoma treated with continuous intravenous infusions of morphine and ketamine combined with amitriptyline for managing cancer pain. Increased dosing of morphine (maximum dose: 42 μg/kg/h) failed to provide adequate pain control. Therefore, combined use of continuous intravenous ketamine (1–1.5 mg/kg/day) and amitriptyline infusions resulted in adequate pain control. Symptoms such as nausea/vomiting, somnolence, and delirium due to continuous infusions of ketamine and amitriptyline combined with morphine were not observed; no analgesia-related respiratory depression was observed. The combined use of continuous intravenous ketamine was effective for morphine-resistant pain. In cases in which there is difficulty in subjective evaluation, adequate pain management could be achieved while considering facial expressions or behaviors (increased nighttime pain) by continuous intravenous infusions of morphine and ketamine combined with antidepressants.