Cardiff School of Biosciences, Cardiff University, Museum Avenue, Cardiff, CF10 3AX, Wales, UK.
Lung. 2020 Feb;198(1):13-21. doi: 10.1007/s00408-019-00305-5. Epub 2019 Dec 13.
Interest in the placebo effect of medicines has developed from the use of placebo treatments as controls in clinical trials into a whole new area of research around how placebos fit into a psychosocial model of therapeutics. The large placebo effect associated with cough medicines is both a problem and an opportunity for researchers: a problem for clinical trials on new actives as the active must beat the large placebo effect, and an opportunity for harnessing the placebo effect to produce effective cough medicines without any pharmacologically active ingredient. This review discusses the mechanisms associated with the placebo effect of cough medicines and distinguishes between a 'perceived placebo effect' and a true 'placebo effect'. The efficacy of sweeteners in cough syrups is discussed as well as viscosity, mucoadhesion, and flavoring. The complexity of modern cough medicines is demonstrated by an example of a medicine which contains one active ingredient, and eighteen excipients which provide a complex and intense sensory experience to enhance the placebo effect and complement the pharmacological activity of the medicine.
人们对药物安慰剂效应的兴趣已经从在临床试验中使用安慰剂治疗作为对照发展到一个全新的研究领域，即研究安慰剂如何融入治疗的心理社会模式。与咳嗽药相关的大的安慰剂效应既是研究人员的一个问题，也是一个机会：对于新活性药物的临床试验来说，这是一个问题，因为活性药物必须克服大的安慰剂效应，而对于利用安慰剂效应来生产没有任何药理活性成分的有效咳嗽药来说，这是一个机会。这篇综述讨论了与咳嗽药安慰剂效应相关的机制，并区分了“感知的安慰剂效应”和真正的“安慰剂效应”。还讨论了甜味剂在咳嗽糖浆中的功效以及粘度、粘膜附着力和调味。通过一个例子说明了现代咳嗽药的复杂性，这个例子包含一种活性成分和十八种赋形剂，这些赋形剂提供了一种复杂而强烈的感官体验，以增强安慰剂效应，并补充药物的药理活性。
