Evidence that the Degree and Duration of Acid Suppression are Related to Helicobacter pylori Eradication by Triple Therapy

Backgrounds and aims: Eradication rates of Helicobacter pylori by a proton pump inhibitor‐based triple therapy depend on CYP2C19 genotype status. We investigated whether gastric acid inhibition during an eradication therapy would influence the eradication rates attained by the triple therapy. Methods: Thirty‐two patients with H. pylori infection underwent the first‐line triple therapy with lansoprazole 30 mg, amoxicillin 750 mg, and clarithromycin 400 mg b.i.d. for 1 week. In all 32 patients, the 24‐hour intragastric pH monitoring was performed on day 6 during the treatment period. Results: The intention‐to‐treat‐based eradication rate by the first‐line therapy was 75.0% (24/32, 95%CI: 56.60–88.54%). In patients with successful eradication, the median 24‐hour pH was 6.4 (range; 5.0–7.6), which was significantly higher than that in patients without eradication [5.2 (2.2–6.2), p = .0131]. The median percentage time of pH 4.0 for a longer postdose time appears to be required for a successful eradication of H. pylori with lansoprazole and acid‐labile antibiotics.