Table 3. Use of proton pump inhibitors and outcome on asthma control.

PEF: peak expiratory flow; FEV1: forced expiratory volume in the first second; FVC: forced vital capacity; PFTs: pulmonary function tests

Reference	Year	Design	Population	Method	Results
Kiljander et al. [46]	2010	Randomized, double-blind, placebo-controlled study	N = 828 asthmatic patients with associated GERD	Esomeprazole 40 mg once or twice daily during 26 weeks	Improvements in PEF and FEV1 were observed in both groups, with no statistically significant differences between treatments
Mastronarde et al. (American Lung Association Asthma Clinical Research Centers) [47]	2009	Randomized, double-blind, placebo-controlled trial	N = 412 patients with poor asthma control and GERD	Esomeprazole 40 mg twice daily or placebo. Follow-up was performed at 24 weeks	Poor asthma control in both groups (2.3 and 2.5 episodes per person-year). No treatment benefit regarding PFTs or quality of life
Shimizu et al. [45]	2006	Randomized, controlled, prospective trial	N= 30 asthmatic patients with GERD	Roxatidine 150 mg daily vs. lansoprazole 30 mg daily	Lansoprazole, in contrast to roxatidine, greatly improved PEF. Neither lansoprazole nor roxatidine led to a change in FEV1
Littner et al. [48]	2005	Multicenter, double-blind, randomized, placebo-controlled trial	N= 207 patients with moderate to severe persistent asthma with GERD	Lansoprazole 30 mg twice daily or placebo. Follow up at 24 weeks	Lansoprazole did not improve daily asthma symptoms, albuterol usage, PEF, FEV1, FVC. Improvement in asthma exacerbations and quality of life
Meier et al. [44]	1994	Double-blind, placebo-controlled crossover study	N= 15 patients with asthma and GERD	Omeprazole 20 mg twice daily for six weeks	Net improvement of more than or equal to 20% in FEV1 in 27 % of patients (4/15)