Zeidler Henning
Hannover Medical School, Carl Neuberg Straße 1, 30625 Hannover, Germany.
Pain Res Treat. 2011;2011:696791. doi: 10.1155/2011/696791. Epub 2011 Jun 6.
This paper addresses the role of paracetamol in placebo-controlled osteoarthritis (OA) trials and the potential contribution to the large placebo response in such trials. Paracetamol is used as rescue medication in nearly all OA placebo-controlled trials. Triggered by the discussion about the placebo effect in general and because of the lack of systematic reviews of placebo effect in OA trials, a recent meta-analysis examined the placebo effect and its potential determinants in the treatment of OA, as the main result came out that placebo is very effective in the treatment of OA, especially for pain, stiffness, and self-reported function. However, mostly limited data are available from published OA trials on the starting dose, final dose, dose over time of paracetamol use, and the percentage of patients who used rescue medication during the study. Paracetamol may be an important additional simulated effect of placebo administration mimicking the true placebo effect and thus a missing link contributing partially to the large placebo response in OA trials. Therefore, the positive effect of paracetamol on symptom relief as well as the need for standardized recording of rescue medication should be taken into account when designing, executing, and interpreting placebo-controlled OA studies.
本文探讨了对乙酰氨基酚在安慰剂对照的骨关节炎（OA）试验中的作用，以及其对这类试验中较大安慰剂反应的潜在影响。在几乎所有OA安慰剂对照试验中，对乙酰氨基酚都用作急救药物。鉴于对一般安慰剂效应的讨论，以及OA试验中缺乏对安慰剂效应的系统评价，最近一项荟萃分析研究了OA治疗中的安慰剂效应及其潜在决定因素，主要结果表明安慰剂在OA治疗中非常有效，尤其是对疼痛、僵硬和自我报告的功能。然而，已发表的OA试验中，关于对乙酰氨基酚起始剂量、最终剂量、用药期间随时间变化的剂量，以及研究期间使用急救药物的患者百分比，大多只有有限的数据。对乙酰氨基酚可能是模拟真实安慰剂效应的安慰剂给药的一种重要附加模拟效应，因此是OA试验中导致较大安慰剂反应的部分缺失环节。所以，在设计、实施和解释安慰剂对照的OA研究时，应考虑对乙酰氨基酚对症状缓解的积极作用以及对急救药物进行标准化记录的必要性。
