Randomised clinical trial: high-dose acid suppression for chronic cough - a double-blind, placebo-controlled study

Area of Science:

• Gastroenterology
• Pulmonology
• Pharmacology

Background:

• Chronic cough can be a symptom of gastro-oesophageal reflux disease (GERD).
• The effectiveness of acid suppression therapy for GERD-related cough remains unclear.
• This study investigates proton pump inhibitors (PPIs) for cough in patients with minimal heartburn symptoms.

Purpose of the Study:

• To evaluate the impact of high-dose acid suppression using proton pump inhibitors (PPIs) on chronic cough.
• To assess outcomes in patients experiencing rare or no heartburn symptoms associated with GERD.
• To determine if PPIs improve cough-specific quality of life and symptom severity.

Main Methods:

• Randomized controlled trial involving 40 non-smoking adults with chronic cough (>8 weeks) and no history of asthma.
• Baseline assessments included 24-h pH/impedance monitoring, methacholine challenge, and laryngoscopy.
• Participants received either high-dose esomeprazole (40 mg twice daily) or placebo for 12 weeks, with outcomes measured by the Cough-Specific Quality of Life Questionnaire (CQLQ) and Fisman Cough Severity/Frequency scores.

Main Results:

• No statistically significant difference was observed in CQLQ scores between the PPI group (mean improvement 9.8) and the placebo group (mean improvement 5.9; P = 0.3).
• Fisman Cough Severity/Frequency scores also showed no significant difference between the two groups.
• The proportion of patients achieving a clinically meaningful improvement (>1 SD) on the CQLQ was similar in both the placebo (27.8%) and PPI (31.8%) groups.

Conclusions:

• High-dose proton pump inhibitor therapy does not significantly improve cough-related quality of life or symptoms in individuals with chronic cough and minimal heartburn.
• These findings suggest that PPIs may not be an effective treatment for GERD-related chronic cough in this specific patient population.
• Further research may be needed to explore alternative mechanisms or treatments for refractory chronic cough.