Effectiveness of two quadruple, tetracycline- or clarithromycin-containing, second-line, Helicobacter pylori eradication therapies

Background: There are no guidelines on second-line therapies for Helicobacter pylori eradication failures of omeprazole-clarithromycin-amoxicillin triple therapy. Aim: To compare the efficacy of two second-line therapies for persistent H. pylori infection. Methods: Over a 6-year period, patients with persistent H. pylori infection following omeprazole-clarithromycin-amoxicillin eradication therapy were randomized to receive omeprazole, 20 mg twice daily, bismuth, 120 mg four times daily, metronidazole, 500 mg twice daily, and either tetracycline, 500 mg four times daily, or clarithromycin, 500 mg twice daily, given for 7 days. Before therapy, patients underwent endoscopy with biopsies for histology, culture and antibiotic susceptibility tests. H. pylori infection was confirmed by histology. Results: Of the 95 randomized patients, 88 (93%,) completed the study. Age, sex, smoking, ulcer/non-ulcer dyspepsia ratio and antibiotic resistance were not significantly different between the treatment groups. On intention-to-treat analysis, eradication was achieved in 41 of the 49 patients (84%: 95% confidence interval, 70.4-92.79%) and 27 of the 46 patients (59%; 95%, confidence interval, 43.3-73.0%) of the tetracycline and clarithromycin-containing groups, respectively (P = 0.007). On multivariate regression analysis, the sensitivity of H. pylori to metronidazole had a likelihood ratio of 5.2 (P = 0.022), followed by the type of quadruple therapy (likelihood ratio, 4.4; P = 0.036). Conclusions: Tetracycline-containing quadruple rescue therapy is highly effective in treating H. pylori eradication failures of the omeprazole-amoxicillin-clarithromycin regimen.