The effect of regular and high doses of omeprazole on the intragastric acidity in patients with bleeding peptic ulcer treated endoscopically:: a clinical trial with continuous intragastric pH monitoring

Objective In peptic ulcer bleeding (PUB), pH level > 4 is considered necessary to prevent dissolving of a formed fibrin clot. The effect of regular or high doses of omeprazole on the intragastric pH in patients with acute PUB was studied. Methods In our earlier study, after endoscopic therapy, PUB patients were randomized to receive a regular dose of intravenous omeprazole (20 mg; i.e. 60 mg/3 days) or a high dose of omeprazole (80 mg bolus + 8 mg/h; i.e. 652 mg/3 days). Of these 142 analysed and reported patients, 13 PUB patients also had intragastric pH. monitoring for these 3 days; seven of these patients had a regular dose and six received a high dose of omeprazole. Results The mean 24-h intragastric pH (regular versus high dose) on day 1 was 4.9 +/- 1.6 versus 6.3 +/- 0.5 (P = 0.035), on day 2 was 4.9 +/- 1.8 versus 6.7 +/- 0.3 (P = 0.001), and on day 3 was 5.7 +/- 1.1 versus 6.7 +/- 0.5 (P = NS). The medians of the intragastric pH were 6 versus 6.5 (P = 0.082) on day 1, 5.8 versus 6.8 (P = 0.001) on day 2, and 6.2 versus 6.8 (P = 0.17) on day 3. The proportion of time when pH < 4 on day 1 was 29.2 +/- 34.1 versus 5.4 +/- 5.7% (P = NS). Conclusions A regular dose of omeprazole raises the mean and median 24-h intragastric pH > 4 in patients with PUB. This reduction in the acidity together with endoscopic therapy is probably sufficient to maintain haemostasis. A high dose of omeprazole keeps the pH almost constantly > 6.