Quantitative gastroesophageal reflux and pulmonary function in asthmatic children and normal adults receiving placebo, theophylline, and metaproterenol sulfate therapy.

There is evidence that theophylline therapy inhibits lower esophageal sphincter pressure and enhances gastroesophageal reflux in normal adults and adult asthmatics. No studies have used intraesophageal pH monitoring to assess the effect of bronchodilators over prolonged periods. With the use of the latter procedure, we studied 10 randomly selected chronic asthmatic children (mean age 10.6 yr) and 10 normal adult subjects; all subjects were without clinical symptoms of GER. In this single-blind study, all subjects were evaluated for GER during three separate 24-hr periods while they were receiving oral doses of placebo, theophylline, and metaproterenol sulfate therapy. No significant increase of GER was found in asthmatic subjects or normal subjects on either drug. No adverse correlation of GER and pulmonary function was noted in either group. Asthmatic subjects and normal subjects had asymptomatic or "silent" physiologic GER during sleep and in the 2-hr postprandial period. This study confirms that in chronic asthmatic children standard oral bronchodilator therapy does not adversely affect "silent" GER or pulmonary functions.