Kosuwon Weerachai, Sirichatiwapee Winai, Wisanuyotin Tweechok, Jeeravipoolvarn Polsak, Laupattarakasem Wiroon
Department of Orthopedics, Faculty of Medicine, Khon Kaen University, Khon Kaen, Thailand.
J Med Assoc Thai. 2010 Oct;93(10):1188-95.
Knee osteoarthritis (OA) is prevalent and associated with both pain and functional disability. Current treatments aim to alleviate mild to moderate symptoms by various methods. Topical capsaicin (0.075% and 0.05%) has been evaluated for the treatment of the painful joints. A burning sensation was the most common side effect at these strengths. Therefore, the authors aimed to evaluate the efficacy of 0.0125% capsaicin gel (Capsika gel) compared to a placebo (the vehicle gel) in patients with symptomatic OA knee.
This was a cross-over; double blinded, randomized, controlled trial of 100 patients with mild to moderate knee OA. All of the patients received either capsaicin gel or placebo gel applied to the affected knee, three times daily for 4 weeks with one week washout period after which the treatment switched to either capsaicin gel or placebo gel for the next 4 weeks. A blinded examiner used the visual analog scale (VAS) and WOMAC score to do weekly assessments.
Subjects averaged 61 years of age (range, 44 to 82). During the enrollment phase, only female farmers presented. Mean body weight and height was 62.97 +/- 10.25 kg and 1.54 +/- 0.053 m, respectively The respective baseline VAS and WOMAC score was 6.40 +/- 1.64 and 51.65 +/- 13.3. The severity of OA, according to the KL criteria was: 83 patients with grade 2 and 16 with grade 3. The respective mean difference of VAS and total WOMAC score in the capsaicin group vs. the placebo group was statistically significant (p < 0.05). The mean difference of the WOMAC pain, stiffness and functional subscales in the capsaicin vs. the placebo group was also significant (p < 0.05). The only adverse event reported was a burning sensation. During the 4-week treatment with capsaicin, approximately 67% of patients had a burning sensation but none withdrew for this reason.
0.0125% capsaicin gel was an effective treatment in mildly to moderately painful OA knees. The burning sensation reported by patients in the capsaicin group was less disturbing than in previous studies and none of the present patients withdrew for this reason.
膝关节骨关节炎（OA）很常见，且与疼痛和功能障碍相关。目前的治疗旨在通过各种方法缓解轻至中度症状。已对局部用辣椒素（0.075%和0.05%）治疗疼痛关节进行了评估。在这些浓度下，烧灼感是最常见的副作用。因此，作者旨在评估0.0125%辣椒素凝胶（Capsika凝胶）与安慰剂（赋形剂凝胶）相比，对有症状的膝骨关节炎患者的疗效。
这是一项交叉、双盲、随机、对照试验，纳入100例轻至中度膝骨关节炎患者。所有患者均接受辣椒素凝胶或安慰剂凝胶涂抹于患膝，每日3次，共4周，有1周洗脱期，之后在接下来的4周内治疗改为辣椒素凝胶或安慰剂凝胶。一名盲法检查者使用视觉模拟量表（VAS）和WOMAC评分进行每周评估。
受试者平均年龄61岁（范围44至82岁）。在入组阶段，仅纳入了女性农民。平均体重和身高分别为62.97±10.25 kg和1.54±0.053 m。各自的基线VAS和WOMAC评分为6.40±1.64和51.65±13.3。根据KL标准，OA的严重程度为：83例2级和16例3级。辣椒素组与安慰剂组的VAS和总WOMAC评分的各自平均差异具有统计学意义（p<0.05）。辣椒素组与安慰剂组在WOMAC疼痛、僵硬和功能子量表方面的平均差异也具有统计学意义（p<0.05）。报告的唯一不良事件是烧灼感。在辣椒素治疗的4周期间，约67%的患者有烧灼感，但无人因此退出。
0.0125%辣椒素凝胶对轻度至中度疼痛的膝骨关节炎是一种有效的治疗方法。辣椒素组患者报告的烧灼感比以往研究中更少困扰，且目前没有患者因此退出。
