Chabal C, Jacobson L, Mariano A, Chaney E, Britell C W
Anesthesiology Department, Veterans Affairs Medical Center, Seattle, Washington 98108.
Anesthesiology. 1992 Apr;76(4):513-7. doi: 10.1097/00000542-199204000-00005.
Neuropathic pain is often a difficult condition to treat. Clinical and laboratory studies using intravenously administered local anesthetics or antiarrhythmic agents support the use of these drugs for the treatment of neuropathic pain. The availability of the oral antiarrhythmic medication, mexiletine, has made it possible to study the effects of an orally administered medication on chronic neuropathic pain. The study used a double-blind placebo-controlled design to examine 11 subjects in whom treatment with conventional pain medications had been unsuccessful. Subjects had a history of peripheral nerve injury or dysfunction, and all complained of symptoms consistent with neuropathic pain. After baseline pain measurements, mexiletine or placebo was given in gradually increasing doses to a maximum daily dose of 750 mg mexiletine. After 1 month at steady state, the subject received the alternative medication. Mexiletine was found to produce a statistically significant reduction in reported pain when compared to baseline or placebo. Pain scores were rated on a scale from 0 (no pain) to 10 (unbearable pain). Median pain scores prior to mexiletine were 7, after placebo treatment 7, and while receiving mexiletine (750 mg/day) 4. Side effects were mild and well-tolerated. Mexiletine may be effective in reducing neuropathic pain for patients in whom alternative pain medications have been unsatisfactory.
神经性疼痛通常是一种难以治疗的病症。使用静脉注射局部麻醉剂或抗心律失常药物的临床和实验室研究支持将这些药物用于治疗神经性疼痛。口服抗心律失常药物美西律的可得性使得研究口服药物对慢性神经性疼痛的影响成为可能。该研究采用双盲安慰剂对照设计，对11名使用传统止痛药治疗无效的受试者进行了检查。受试者有周围神经损伤或功能障碍史，且均主诉有与神经性疼痛相符的症状。在进行基线疼痛测量后，逐渐增加美西律或安慰剂的剂量，直至美西律的最大日剂量为750毫克。在稳定状态下服用1个月后，受试者换用另一种药物。与基线或安慰剂相比，发现美西律能使报告的疼痛在统计学上显著减轻。疼痛评分采用从0（无疼痛）到10（难以忍受的疼痛）的量表进行评定。服用美西律前的中位疼痛评分为7分，服用安慰剂治疗后为7分，而服用美西律（750毫克/天）时为4分。副作用轻微且耐受性良好。对于使用其他止痛药效果不佳的患者，美西律可能有效减轻神经性疼痛。
