Methadone for Pain Management in Chemotherapy-Induced Peripheral Neuropathy: A Retrospective Review

Chemotherapy-Induced Peripheral Neuropathy (CIPN) refers to damage of peripheral nerve fibers due to the use of neurotoxic chemotherapy to treat various cancers. It occurs in more than 30% of patients and only duloxetine has currently been identified to show limited efficacy in symptomatic treatment of CIPN. Opioids have traditionally been used to treat cancer pain, and there is evidence for their use in treatment of peripheral neuropathic pain from other causes. With a similar mechanism of action to duloxetine, methadone has rationale for treating neuropathic pain. This study is a retrospective chart review to evaluate the outcomes of using methadone for CIPN pain. Out of 31 patients, 65% felt that methadone was an effective treatment, 19% felt that it was ineffective, and 16% felt that it was partially or temporarily effective. These results suggest that analgesic response to methadone varies between patients, but that it has a potential role in painful CIPN. Its advantages for long-term use include low cost and lack of metabolites. Potential risks include a long half-life, drug interactions, and potential for QT prolongation at high doses. Prospective studies should be conducted to evaluate the role of methadone in CIPN pain management more comprehensively.