Chronic cough and esomeprazole: A double-blind placebo-controlled parallel study

Background and objective: Gastro-oesophageal reflux has been implicated in the pathogenesis of chronic cough. Guidelines on management suggest a therapeutic trial of anti-reflux medication. Esomeprazole is a proton pump inhibitor licensed for the long-term treatment of acid reflux in adults and we compared the effects of esomeprazole and placebo on patients with chronic cough. Methods: This was a prospective, single-centre, randomized, double-blind, placebo-controlled, parallel group study conducted over 8 weeks. Fifty adult nonsmokers with chronic cough and normal spirometry were randomized. Patients completed cough-related quality-of-life and symptom questionnaires and subjective scores of cough frequency and severity at the beginning and end of the study. They also kept a daily diary of symptom scores. Citric acid cough challenge and laryngoscopic examination were performed at baseline and the end of the study. The primary outcome was improvement in cough score. Results: There were no differences in cough scores in the placebo and treatment arms of the study although some significant improvements were noted when compared to baseline. In the cough diary scores there was a trend towards greater improvement in the treatment arm in patients with dyspepsia. Conclusions: Esomeprazole did not have a clinically important effect greater than placebo in patients with cough. It suggests a marked placebo effect in the treatment of cough.