Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Importance of placebo effect in cough clinical trials

Eccles, Ronald ORCID: https://orcid.org/0000-0001-9492-2062 2010. Importance of placebo effect in cough clinical trials. Lung 188 (S1) , pp. 53-61. 10.1007/s00408-009-9173-3

Full text not available from this repository.

Abstract

Cough is a unique symptom because, unlike sneeze and other symptoms, it can be under voluntary control and this complicates clinical trials on cough medicines. All over-the-counter cough medicines (OTC) are very effective treatments because of their placebo effect. The placebo effect is enhanced by expectancy related to advertising, brand, packaging, and formulation. This placebo effect creates a problem for the conduct of clinical trials on OTC cough medicines that attempt to demonstrate the efficacy of a pharmacological agent above that of any placebo effect. Up to 85% of the efficacy of some cough medicines can be attributed to a placebo effect. The placebo effect apparent in clinical trials consists of several components: natural recovery, regression of cough response toward mean, demulcent effect, effect of sweetness, voluntary control, and effects related to expectancy and meaning of the treatment. The placebo effect has been studied most in the pain model, and placebo analgesia is reported to depend on the activation of endogenous opioid systems in the brain; this model may be applicable to cough. A balanced placebo design may help to control for the placebo effect, but this trial design may not be acceptable due to deception of patients. The placebo effect in clinical trials may be controlled by use of a crossover design, where feasible, and the changes in the magnitude of the placebo effect in this study design are discussed.

Item Type: Article
Date Type: Publication
Status: Published
Schools: Biosciences
Subjects: R Medicine > RA Public aspects of medicine > RA0421 Public health. Hygiene. Preventive Medicine
R Medicine > RM Therapeutics. Pharmacology
Uncontrolled Keywords: placebo effect ; acute cough ; codeine ; voluntary control ; clinical trial
Publisher: Springer New York
ISSN: 0341-2040
Last Modified: 19 Oct 2022 08:40
URI: https://orca.cardiff.ac.uk/id/eprint/18690

Citation Data

Cited 21 times in Scopus. View in Scopus. Powered By Scopus® Data

Actions (repository staff only)

Edit Item Edit Item