Effect of different doses of omeprazole on 24‐hour oesophageal acid exposure in patients with gastro‐oesophageal reflux

Abstract

To define the optimum doses of omeprazole appropriate for acute and long‐term therapy of patients with gastro‐oesophageal reflux disease, 24‐h oesophageal pH was measured in 12 patients with symptomatic reflux and an abnormal 24‐h oesophageal acid exposure time (> 6%) in a randomized, double‐blind, four‐way crossover study comparing the effects of omeprazole 10, 20, or 40 mg/day and placebo. Total reflux time over 24 hours, number of reflux episodes per hour, and the number of reflux episodes lasting > 5 minutes were measured by ambulatory 24‐h oesophageal pH monitoring. All doses of omeprazole were superior to placebo in decreasing gastro‐oesophageal reflux as measured by each index. With placebo, oesophageal acid exposure was 16.3 % of the 24 hours, 10 mg omeprazole/day reduced that to 6.3 %, 20 mg/day lowered acid exposure to 0.9%, and 40 mg/day to 0.6%. Thus only the 20 and 40 mg doses reduced acid exposure to within the normal range. Similar results were obtained with the other indices of reflux. These data suggest that a rational dose regimen for reflux oesophagitis is 20 mg/day, a regimen that has proved effective in clinical trials. The present study indicates that 24‐hour oesophageal pH monitoring is a practical approach to the determination of drug dosage in patients with gastro‐oesophageal reflux.