Study of Acid Reflux in Asthma

BACKGROUND: Gastroesophageal reflux (GERD) is frequent in asthmatics with poor asthma control, often occurs without symptoms, and can induce bronchoconstriction. Poorly controlled asthmatics are often treated for GERD with drugs that suppress gastric acid, but this treatment is expensive and the benefit of such treatment is not established. Proton pump inhibitors are a relatively new class of medications that provide highly effective treatment for GERD and associated problems. This success has led many doctors to begin PPI treatment in their asthma patients in an attempt to achieve better asthma control. DESIGN NARRATIVE: The randomized, placebo-controlled trial will enroll 400 asthmatics, ages 18 or older, who have poor asthma control on inhaled steroids, defined on the basis of excessive bronchodilator use, nocturnal awakenings, or frequent exacerbations. Participants will be randomly assigned to treatment with either a proton pump inhibitor, esomeprazole (Nexium) 40 mg twice a day, or matching placebo. The presence, severity, and temporal relationship of GERD to asthma symptoms will be documented with 24 hour ambulatory esophageal potential Hydrogen (pH) probe monitoring, but participants will be enrolled irrespective of the severity of GERD. The primary outcome measure is the proportion of participants who have exacerbations of asthma within a 6-month period defined by asthma diaries and interviews. Secondary outcome measures include asthma symptom and control scores, asthma-specific and generic health-related quality of life, GERD symptoms, health care use, pulmonary function, and airways reactivity. Pre-specified subgroup analyses will be conducted to determine if there are clinical or demographic characteristics that predict benefit from treatment of GERD in asthma.