School of Medicine, Queen's University, Kingston, Canada.
Faculty of Medicine, University of Ottawa, Ottawa, Canada.
Pain Med. 2021 Dec 11;22(12):2896-2907. doi: 10.1093/pm/pnab042.
To assess the efficacy and safety of N-acetylcysteine in the treatment of chronic pain.
A systematic search was carried out until April 2020 for clinical studies of N-acetylcysteine in the management of any persistent or recurrent chronic pain condition for adults ≥ 18 years old. Risk of bias was assessed using the validated risk of bias tools. When appropriate, a meta-analysis using a random-effects model was performed, with a fixed-effect model for sensitivity analysis.
Nine studies (n = 863) were included (five randomized controlled trials [RCTs], two open-label non-comparative studies and two comparative studies), that evaluated patients with sickle cell disease (3), complex regional pain syndrome (1), pelvic pain/endometriosis (2), rheumatoid arthritis (1), diabetic neuropathy (1), and chronic neuropathic pain (1). In the pooled analysis of three RCTs, N-acetylcysteine did not reduce pain intensities (SMD -0.21, 95% confidence interval [CI]: -0.33 to 0.75, random-effects), improve functional outcomes (SMD 0.21, 95% CI -0.33 to 0.75) or quality of life (SMD 0.60, 95% CI: -4.44 to 5.64); however, sensitivity analysis with a fixed effect model demonstrated an effect for pain intensities and function. Due to adverse events being inconsistently reported, no conclusion could be made regarding safety of N-acetylcysteine in chronic pain.
While there is some evidence to indicate N-acetylcysteine may provide analgesic efficacy for certain pain conditions, there is insufficient evidence to provide definitive evidence on NAC in chronic pain management. Larger-size RCTs spanning a variety of chronic pain conditions are needed to determine N-acetylcysteine's role, if any, in pain medicine.
评估 N-乙酰半胱氨酸治疗慢性疼痛的疗效和安全性。
系统检索截至 2020 年 4 月，关于 N-乙酰半胱氨酸治疗成人（≥18 岁）任何持续性或复发性慢性疼痛疾病的临床研究。使用经过验证的偏倚风险工具评估偏倚风险。在适当的情况下，使用随机效应模型进行荟萃分析，并进行固定效应模型的敏感性分析。
纳入 9 项研究（n=863）（5 项随机对照试验[RCT]、2 项开放标签非对照研究和 2 项对照研究），评估了镰状细胞病（3）、复杂区域疼痛综合征（1）、盆腔疼痛/子宫内膜异位症（2）、类风湿关节炎（1）、糖尿病性神经病（1）和慢性神经性疼痛（1）患者。在 3 项 RCT 的汇总分析中，N-乙酰半胱氨酸未降低疼痛强度（SMD-0.21，95%置信区间[CI]：-0.33 至 0.75，随机效应）、改善功能结局（SMD 0.21，95%CI：-0.33 至 0.75）或生活质量（SMD 0.60，95%CI：-4.44 至 5.64）；然而，使用固定效应模型进行敏感性分析显示，疼痛强度和功能存在影响。由于不良反应报告不一致，无法确定 N-乙酰半胱氨酸治疗慢性疼痛的安全性。
虽然有一些证据表明 N-乙酰半胱氨酸可能对某些疼痛疾病具有镇痛疗效，但尚无足够证据提供 NAC 在慢性疼痛管理方面的明确证据。需要开展更大规模的 RCT，涵盖各种慢性疼痛疾病，以确定 N-乙酰半胱氨酸在疼痛医学中的作用（如果有）。
