Should Acid Suppressive Therapy Improve Chronic Cough? (Chest 2013;143:605-612)

Abstract

Gastroesophageal reflux disease (GERD) may cause laryngopharyngeal reflux, which results in mucosal exposure of the pharynx, larynx, or pulmonary system to the different components of the gastric refluxate, and so provokes symptoms including throat discomfort, hoarseness, globus pharyngeus and chronic cough. Chronic cough, defined as a cough lasting more than 8 weeks, is a common problem in primary care. The most common etiology of chronic cough in adults is upper airway cough syndrome secondary to postnasal drip, asthma, or GERD.1 Kahrilas et al2 has recently reported a systemic review regarding response of chronic cough to acid suppressive therapy in patients with GERD.2 A systemic search of Pubmed and Embase was conducted, which included placebo-controlled clinical trials reporting data on the effect of acid suppressive therapy on chronic cough in patients with GERD or laryngopharyngeal reflux by objective measures and/or reflux symptoms. Finally, they reviewed nine randomized controlled trials that treated patients with acid suppression. Among them, 8 trials used proton pump inhibitors (PPIs; daily or bid for 8-16 weeks),while 1 trial used ranitidine. Therapeutic gain was greater in patients with pathologic esophageal acid exposure (mean 21.5%; range, 12.5-35.8%) than in those without pathologic esophageal acid exposure (range, 0.0-8.6%). Patients with heartburn were excluded from the 2 studies which included patients without acid exposure. The mean placebo response rate was 13.8%. Although study design and subjective outcomes were variable in each study, the authors concluded that a therapeutic benefit for acid suppressive therapy in patients with chronic cough cannot be dismissed. It would be much more effective in selective patients who are favorable to therapy based on symptoms or reflux testing.