Wong CH et al. (2006) Gastro-oesophageal reflux disease in 'difficult-to-control' asthma: prevalence and response to treatment with acid suppressive therapy. Aliment Pharmacol Ther 23: 1321–1327

Gastroesophageal reflux disease (GERD) is thought to contribute to several pulmonary disorders, including asthma, via reflux (microaspiration of gastric acid to the airways and lungs) and reflex (an acid-stimulated vagal nerve reflex arc) mechanisms. Although some GERD treatments improve asthma symptoms in patients with GERD and asthma, studies on the effect of proton-pump inhibitors (PPIs) have yielded mixed results. Wong et al. found that over 50% of patients with difficult-to-control asthma (who experience persistent asthma despite optimized medication) also had GERD. When given PPIs, three-quarters of these patients reported improvement in their asthma symptoms, even though asthma medications were unchanged.

This single-center, prospective study carried out in Malaysia recruited 30 patients with difficult-to-control asthma (17 also had GERD). Subjective and objective measures of esophageal and pulmonary symptoms were assessed at baseline and after 8 weeks of daily 30 mg lansoprazole, by follow-up investigators blinded to baseline data. Asthma symptoms decreased significantly only in the patients with GERD (P = 0.002). As in previous studies, no improvement in lung function was seen in this group; however, the authors suggest that a change might be detected with either a larger sample size or longer study, as subjective might precede objective improvements in symptoms.

In studies of GERD and asthma, the authors emphasize the importance of establishing adequate acid suppression. They note that the PPI dose used for these Asian patients (who generally have small body frames) might need adjusting for different patient populations.