Effect of frequent dosing of an oral proton pump inhibitor on intragastric pH

Abstract

Background: Treatment with a continuous i.v. proton pump inhibitor is presumed to promote clot formation and stability by sustaining intragastric pH≥6. Aim: We postulated that very frequent oral dosing of proton pump inhibitors should simulate i.v. infusion and achieve similar pH control. Methods: Twenty healthy volunteers were stratified by Helicobacter pylori status (10 positive; 10 negative) and had determination of CYP2C19 status. After an overnight fast, an intragastric pH probe was placed. Subjects received 120 mg of lansoprazole at 8 am and 30 mg every 3 h until 8 pm. Results: Intragastric pH was measured over 24 h, and lansoprazole plasma concentrations were determined at five time points. Intragastric pH was ≥6 for 41% (95% CI: 30-53%) of the 15-h period from 8 am-11 pm and 46% (95% CI: 35-56%) of the 24-h period (8-8 am). The mean proportion of patients with pH ≥6 was not significantly different in H. pylori-positive vs. negative patients. Only 25% of subjects sustained pH ≥6 for at least 60% of the 15-h period, and 35% had a sustained pH ≥6 for at least 60% of the 24-h period. Conclusions: A dose of 120 mg of oral lansoprazole followed by standard 30 mg doses of lansoprazole every 3 h did not reliably sustain pH at the desired level of 6. © 2006 Blackwell Publishing Ltd.