Effect of Repeated Bolus Injection, Low- or High-Dose Continuous Infusion of Omeprazole on Intragastric pH in Patients With Bleeding Peptic Ulcer via Dose-Titration Study

Abstract

Effect of Repeated Bolus Injection, Low or High Dose Continuous Infusion of Omeprazole on Intragastric pH in Patients With Bleeding Peptic Ulcer v a Dose-Titration Study Philip Wai Y., Simon Kin Hung Wong, Justin Chi Yuen Wu, Man Yee Yung, Wilfred Mui, Enders Kwok Wai Ng, James Yun Wong Lau, Joseph Sung Aim: From our previous study, we have shown that the adjunctive use of high dose omeprazole infusion reduced the rate of recurrent bleeding after endoscopic hemostasis for bleeding peptic ulcers. The appropriate dose of omeprazole to achieve optimal pH profile for clot stability is unknown. The aim of this study is to define the gastric acid suppression profile among various regimens of adjunctive omeprazole. Patients and Method: We included patients that presented with bleeding peptic ulcers and had endoscopic stigmata of either red dot or clean base that do not required endoscopic treatment. We excluded those that received regular antisecretory medications, NSAID/aspirin users, previous gastric surgery and moribund patients. All patients were randomly assigned to receive various dosage protocol of proton pump inhibitor for 24 hours, including 1. Omeprazole 80 mg bolus, then 8 mg/hr infusion (192 mg/d); 2. Omeprazole 80 mg bolus, then 4 mg/hr infusion (96 mg/d); or 3. Omeprazole intravenous 40 mg bolus 6 hourly (160 mg/d). We measured the 24 hour fasting gastric pH with the electrode positioned at 10 cm below the gastroesophageal junction. We collected the median pH, % time pH O 4 and % time pH O 6 at intervals of 1 hour, 4 hour, 12 hour and 24 hours after the start of therapy. We also analyzed the time needed to attain pH O 4 and pH O 6. Results: We included 30 patients with bleeding peptic ulcers that had endoscopic stigmata of either red dot or clean base. 11 patients received omeprazole 40 mg every 6 hourly, 10 patients received omeprazole 4mg/hr and 9 patients received omeprazole 8 mg/hr. The three groups were comparable in terms of age, body weight, ulcer size, initial blood pressure and hemoglobin level. There was no difference in the % time pH O 4 or 6 at 1, 4, 12 and 24 hours between the three groups. However, we found that those patients receiving omeprazole 8 mg/hr could reach pH O 4 in a significantly shorter time (Kruskal-Wallis test p Z 0.04) (Figure 1). Conclusion: Patients receiving a regime of high dose omeprazole infusion at 8mg/hr attained an intragastric pH profile of more than 4 in a significantly shorter period of time. A high dose regimen may be more effective in prevention of early recurrent rebleeding by early clot stabilization.