Fuchs Perry N, Pappagallo Marco, Meyer Richard A
Department of Neurosurgery, Johns Hopkins School of Medicine, 600 North Wolfe Street, Meyer 5-109, Baltimore, MD 21287 USA Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD USA Applied Physics Laboratory, The Johns Hopkins University, Johns Hopkins Road, Laurel, MD 20723, USA.
Pain. 1999 Apr;80(3):637-642. doi: 10.1016/S0304-3959(98)00260-7.
Topical capsaicin has been reported to be beneficial for the treatment of neurogenic pain. However, due to the burning pain associated with topical capsaicin, many patients discontinue treatment before therapeutic benefits are obtained. This study assessed the efficacy of EMLA (eutectic mixture of 2.5% prilocaine and 2.5% lidocaine) to block pain induced by the topical application of 1% capsaicin. Nine healthy subjects (five males and four females) participated in the study. High dose topical capsaicin (1%) was applied to a 2.5 x 2.5 cm region of both volar forearms for 6 h. One arm was pretreated (for 2 h) and cotreated with EMLA, and the other arm served as vehicle control. Average and peak pain ratings were recorded at 15-min intervals using a 0 (no pain) to 10 (worst possible pain) scale. Average and peak pain ratings were significantly lower at the EMLA site during the first 15-30 min of capsaicin treatment. However, for the remaining 5.5 h of capsaicin treatment, the pain ratings at the EMLA and vehicle sites were not significantly different. The 6 h treatment with high dose topical capsaicin (1%) produced significant desensitization to heat stimuli that was not affected by EMLA treatment. EMLA fails to produce a long lasting attenuation of the pain induced by topical application of 1% capsaicin. These results argue against the use of EMLA to block pain to topical capsaicin during the treatment of neurogenic pain.
据报道，局部应用辣椒素对治疗神经源性疼痛有益。然而，由于局部应用辣椒素会引起灼痛，许多患者在获得治疗益处之前就停止了治疗。本研究评估了复方利多卡因乳膏（2.5%丙胺卡因和2.5%利多卡因的共熔混合物）阻断局部应用1%辣椒素所诱发疼痛的效果。九名健康受试者（五名男性和四名女性）参与了该研究。将高剂量局部辣椒素（1%）涂抹于双侧前臂掌侧2.5×2.5 cm的区域，持续6小时。一只手臂预先用复方利多卡因乳膏处理（2小时）并同时使用该乳膏，另一只手臂作为赋形剂对照。使用0（无疼痛）至10（可能的最严重疼痛）的评分量表，每隔15分钟记录平均疼痛评分和峰值疼痛评分。在辣椒素治疗的前15至30分钟内，复方利多卡因乳膏处理部位的平均疼痛评分和峰值疼痛评分显著较低。然而，在辣椒素治疗的其余5.5小时内，复方利多卡因乳膏处理部位和赋形剂对照部位的疼痛评分无显著差异。高剂量局部辣椒素（1%）6小时的治疗对热刺激产生了显著的脱敏作用，且不受复方利多卡因乳膏治疗的影响。复方利多卡因乳膏未能长期减轻局部应用1%辣椒素所诱发的疼痛。这些结果不支持在神经源性疼痛治疗中使用复方利多卡因乳膏来阻断局部应用辣椒素所引起的疼痛。
