title: Ultra-low dose ketamine and memantine treatment for pain in an opioid-tolerant oncology patient.
abstract: Patients taking high-dose opioids chronically for tumor-related or neuropathic pain may develop pain that is refractory to opioids. One option for control of such pain is the use of the N-methyl-D-aspartate (NMDA) receptor antagonist ketamine. We describe a case of opioid-refractory pain that responded to a low-dose IV infusion of ketamine in the inpatient setting. The patient was then successfully transitioned to oral memantine for long-term outpatient management, in a novel use of this oral NMDA receptor antagonist. We present recent findings from basic research on pain mechanisms to explain why opioid tolerance, as in this patient, may contribute to the analgesic benefit of NMDA receptor antagonists.
authors.affiliation: Department of Anesthesiology and Graduate Program in Neurobiology and Behavior, Box 356540, University of Washington, Seattle, WA 98195, USA.
authors.forename: Lucinda A
authors.initials: LA
authors.lastname: Grande
authors.forename: Brendan R
authors.initials: BR
authors.lastname: O'Donnell
authors.forename: Dermot R
authors.initials: DR
authors.lastname: Fitzgibbon
authors.forename: Gregory W
authors.initials: GW
authors.lastname: Terman
mesh_terms: D000328:Adult; D000700:Analgesics / Q000008:administration & dosage*; D000701:Analgesics, Opioid / Q000627:therapeutic use; D004361:Drug Tolerance; D006801:Humans; D007649:Ketamine / Q000008:administration & dosage*; D008080:Liposarcoma / Q000150:complications* / Q000556:secondary; D008297:Male; D008559:Memantine / Q000008:administration & dosage*; D010147:Pain Measurement; D010148:Intractable Pain / Q000188:drug therapy* / Q000209:etiology; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors*; D013125:Spinal Neoplasms / Q000150:complications*
chemical_list: D000700:Analgesics; D000701:Analgesics, Opioid; D016194:Receptors, N-Methyl-D-Aspartate; D007649:Ketamine; D008559:Memantine