Mexiletine as an Adjuvant Analgesic for the Management of Neuropathic Cancer Pain

Abstract

Ancer pain can usually be managed with stan- dard analgesic regimens; however, neuropathic pain related to tumor infiltration of major plexi can be difficult to control. Neuropathic pain is defined as pain caused by injury to or dysfunction of the peripheral or central nervous system (1). Mexiletine, a class 1b antiarrhythmic and orally available local an- esthetic sodium channel blocker structurally similar to lidocaine, has been suggested for the treatment of chronic neuropathic pain (2- 4). Although mexiletine has been suggested in the management of neuropathic cancer pain, few data are available in the literature to support such use. We report the use of mexiletine as an adjuvant analgesic to provide pain relief for three patients with neuropathic cancer pain secondary to lumbosacral plexus tumor infiltration. All patients continued their current opioid at a constant level during the trial of mexiletine. Mexiletine was added as an adjuvant an- algesic with a starting dose of 200 mg BID, increased to 200 mg TID as required for analgesia. Twice daily visual analog scales (VAS) were completed for pain and nausea (0 5 no pain to 10 5 worst possible pain). The use of any additional analgesics and any side effects were recorded daily.