Lidocaine and similar local anesthetics are effective for treating pain that emanates from damaged nerves, according to a systematic review of current evidence.
Neuropathic pain, which can occur with chronic diseases or conditions, is frequently unresponsive to treatment and worsens over time.
"Intravenous lidocaine and oral derivatives relieve pain from damage to the nervous system," found authors Ivo W. Tremont-Lukats, M.D., of the M.D. Anderson Cancer Center in Houston, and colleagues. They add that the drugs, "were safe in controlled clinical trials for neuropathic pain, were better than placebo and were as effective as other analgesics."
The review appears in the most recent issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.
The authors reviewed 30 studies on the effectiveness of lidocaine and similar drugs mexiletine, tocainide and flecainide in treating pain. Local anesthetics work by decreasing sensation in a small area of the body.
The studies covered 371 patients given local anesthetics and 379 patients given placebos. The patients studied had pain from cerebrovascular lesions or tumors, spinal cord injuries, multiple sclerosis, amputation and a variety of other causes, including pain for which there was no apparent cause.
Patients rated the intensity of spontaneous pain or its relief. Lidocaine administered by pump and mexiletine provided the best relief. However, there were some side effects reported, the most common being sleepiness, fatigue, nausea, numbness around the mouth, metallic taste and dizziness.
"For some patients in certain pain categories, lidocaine may be as good as other current therapies," Tremont-Lukats says, "This systematic review found that lidocaine and mexiletine were equally effective, unlike other reviews previously stating that mexiletine seemed to work better."