OBJECTIVE:To determine the efficacy of pantoprazole therapy for daytime somnolence, psychomotor vigilance, and quality of life in patients with mild-moderate obstructive sleep disordered breathing (OSDB) and gastroesophageal reflux disease (GERD). STUDY DESIGN:Randomized, double-blind, placebo-controlled crossover trial. METHODS:Sixty patients with daytime sleepiness, mild-moderate OSDB and GERD were randomly assigned a 2-week treatment with pantoprazole 40 mg or placebo followed by a 2-week washout period and crossover respectively to 2-week treatment with placebo or pantoprazole. Outcomes included Epworth Sleepiness Score (ESS), sleep-related quality-of-life (FOSQ), and reaction time. RESULTS:With pantoprazole, patients reported statistically significantly greater improvement of overall reflux symptoms (P = 0.0003) and in ESS (P = 0.04). A significant improvement was noted in FOSQ for both treatments with a trend toward greater improvement with pantoprazole (P = 0.058). No improvement in reaction times was observed. CONCLUSION:Patients with coexistent GERD and OSDB noted significant improvement in daytime sleepiness after treatment with pantoprazole over placebo likely related to a reduction in nocturnal reflux-related arousals.