A Successful Case of Switching Treatment from Ketamine to Methadone for Complex Neuropathic Pain

Methadone is frequently used for the management of complex pain at the end of life by palliative care specialists. It is also used in low doses as an add-on therapy to chronic opioid treatment of cancer-related pain, usually with good effect, and without any reported severe adverse effects. However, there are few reports of switching from ketamine to methadone. We report a case of a patient with rectal cancer and intractable pain. Switching from ketamine to methadone to maintain analgesia was successfully carried out without impacting activities of daily living. Established measurement tools, such as numerical rating scale, Douleur Neuropathique, Functional Independence Measure, and Barthel Index, were used. Switching from ketamine to methadone may be beneficial in relieving refractory cancer-related neuropathic pain without decreasing functioning.