The effect of intragastric acidity on Helicobacter pylori eradication withbismuth-metronidazole-amoxicillin

BACKGROUND/AIMS: Adding an acid secretion inhibitor to anti-H. pylori regim ens may be potentially valuable for enhancing the effectiveness of antimicr obials that exhibit markedly reduced activity at low pH. This study was con ducted to evaluate intragastric acidity as a factor in H. pylori eradicatio n with bismuth-based triple therapy. METHODOLOGY: Forty patients with duodenal ulcer and H. pylori infection wer e included. The patients were divided into 2 groups - normacid (n=20) and h yperacid (n=20) - based on the amount of time that 24-hour intragastric pH took to reach the level pH greater than or equal to 3. All patients receive d bismuth subsalicylate (600mg 3 times daily), metronidazole (500mg 3 times daily) and amoxicillin (500mg 3 times daily) for 2 weeks. Then, all patien ts continued treatment with ranitidine (150mg twice daily) for 8 weeks prio r to the follow-up examination. Blood samples were collected before treatme nt for measurement of fasting gastrin and pepsinogen-I. RESULTS: Nine patients (45%) in the normacid group and 8 patients (40%) in the hyperacid group reported side effects. However, there were only 2 patie nts (10%) in each group who withdrew from the study due to intolerance of s ide-effects. There was no difference in the H. pylori eradication rate betw een the normacid and hyperacid groups (16/18, 88.9% vs. 15/18, 83.3%). CONCLUSIONS: Without co-administration of anti-secretary agents, intragastr ic acid is not; a significant factor in the effectiveness of H. pylori erad ication with bismuth-based triple therapy.