High Dose Amoxicillin Versus Tetracycline as Second-line Treatment of Resistant Helicobacter Pylori Infection
Condition: Helicobacter Pylori Treatment Failure
MeSH terms: Infections
Study type: Interventional
Phase: Phase 4

Summary: 
      No trial has examined the the efficacy of high dose amoxicillin based quadruple therapy as
      second-line treatment for Helicobacter pylori infection. The study aims to compare the
      effectiveness and safety of 14-day high dose amoxicillin-based quadruple regiment with
      classical quadruple regiment for rescue eradication of Helicobacter pylori.
    

Detailed description: 
      Helicobacter pylori is the most successful human pathogen infecting an estimated 50% of the
      global population, and is associated with a spectrum of disease states, including chronic
      gastritis, duodenal and gastric ulcer, gastric adenocarcinoma, and gastric mucosa-associated
      lymphoid tissue lymphoma (MALToma).

      Most Consensus Conferences and Clinical Guidelines recommend the prescription of a triple
      therapy including a proton pump inhibitor (PPI) and clarithromycin with either amoxicillin or
      metronidazole, as first-line treatment. However, the effectiveness of these triple-therapy
      regimens seems to have diminished over time, largely as a result of emerging resistance of
      the organism to clarithromycin. Avoiding problems due to antibiotic resistance has become an
      important issue when deciding a second-line rescue therapy for H. pylori infection

      Bismuth-containing quadruple therapies have been used widely in second-line therapy of H.
      pylori infection, and are recommended by the Maastricht IV Consensus Conference report.
      Quadruple therapy can achieve a high rate of eradication success as a second-line treatment.
      A meta-analysis of quadruple therapy showed that metronidazole resistance had limited effect
      on the outcome when adequate dosages and durations are used. This meta-analysis also showed
      that compliance with quadruple therapy is high. Classical bismuth-based quadruple therapy
      consists of a PPI, bismuth, tetracycline and metronidazole. This regiment meets the proposed
      criteria for a second-line treatment: it does not contain the key antibiotic of the original
      regimen (clarithromycin), the treatment is not affected by clarithromycin resistance,
      metronidazole resistance in vitro does not affect the outcome of quadruple therapy
      significantly, compliance with the regimen is high and the regimen is effective in most parts
      of the world. But this regiment has high rate of side effects because of tetracycline.

      Amoxicillin has low resistance rate as well as low percentage of side effects. The
      replacement of tetracycline by high dose amoxicillin in classical bismuth-containing
      quadruple therapy may be a better choice. Therefore, we will do a randomized trial to compare
      the eradication rate of 14-day high dose amoxicillin and metronidazole based
      bismuth-containing quadruple therapy with classical quadruple therapy for second-line
      Helicobacter pylori treatment.
    

Intervention name(s): Lansoprazole; Bismuth Potassium Citrate; Metronidazole; Amoxicillin; Tetracycline
Intervention type(s): Drug; Drug; Drug; Drug; Drug
Intervention description(s): antisecretory drug of each quadruple therapy; one component of each quadruple therapy; antibiotic of each quadruple therapy; antibiotic of high dose amoxicillin based quadruple therapy; antibiotic of classical quadruple therapy
Other intervention name(s): proton pump inhibitor; Bismuth; antibiotic; antibiotic; antibiotic
Intervention MeSH terms: Anti-Bacterial Agents; Amoxicillin; Metronidazole; Tetracycline; Antibiotics, Antitubercular; Potassium Citrate; Lansoprazole; Bismuth; Proton Pump Inhibitors
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: None (Open Label)
Primary purpose: Treatment
Keywords: Helicobacter pylori; Treatment Failure; second-line therapy