Effects of oral rabeprazole on oesophageal and gastric pH in patients with gastro‐oesophageal reflux disease

Abstract

Background This study examined the dose–response effects of the new proton‐pump inhibitor rabeprazole on oesophageal and gastric pH in patients with gastro‐oesophageal reflux disease. Methods This study had a single‐centre, double‐blind, randomized, two‐way crossover design. Twenty patients were treated for two 7‐day periods separated by a 7–10‐day washout period. Patients were randomly assigned to receive either 20 mg of rabeprazole once daily during the first treatment period and 40 mg once daily during the second treatment period, or 40 mg during the first treatment period and 20 mg during the second treatment period. The primary efficacy variable was oesophageal acid exposure determined by 24‐hour ambulatory pH monitoring. Acid‐reflux time was defined as the percentage of time over 24 h that oesophageal pH was 5 min, with no significant differences between dosages for any reflux parameter. Mean gastric pH increased with 20 mg from 1.86 at baseline to 3.71 on day 1 and 4.17 on day 7. Rabeprazole 40 mg once daily increased gastric pH from 2.01 to 4.37 on day 1, and to 4.65 on day 7. Safety analyses revealed no significant acute side‐effects for either dosage. Conclusions Pathological oesophageal acid exposure was normalized with both 20 mg and 40 mg dosages of rabeprazole, and the effects of these two doses did not differ. Rabeprazole was well‐tolerated in this short‐term study.