EFFECTS OF ORAL RABEPRAZOLE ON ESOPHAGEAL AND GASTRIC PH IN PATIENTS WITH GASTROESOPHAGEAL REFLUX DISEASE

Background: This study examined the dose-response effects of the new p roton-pump inhibitor rabeprazole on oesophageal and gastric pH in pati ents with gastrooesophageal reflux disease, Methods: This study had a single-centre, double-blind, randomized, two-way crossover design. Twe nty patients were treated for two 7-day periods separated by a 7-10-da y 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 <4, A dosage was considered effective if reflux time was reduced to <6%, a number w hich has been our internal laboratory reference, Results: Both rabepra zole 20 mg and 40 mg, given once daily, normalized reflux time, with d ecreases of 79% and 92% in acid exposure by day 7. Both dosages also d ecreased the mean total number of reflux episodes and the number of ep isodes lasting >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 I 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 4.6 5 on day 7, Safety analyses revealed no significant acute side-effects for either dosage. Conclusions: Pathological oesophageal acid exposur e 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-t olerated in this short-term study.