This prospective controlled randomized open-label clinical trial is designed to determine the optimal eradication rate of rabeprazole based sequential-concommitant hybrid therapies for adults infected with Helicobacter pylori in Eastern Taiwan. Enrolled patients will receive 3, 5 or 7 days of pre-concommitant (sequential part) treatment with rabeprazole + amoxicillin, then 7 days of concommitant treatment with rabeprazole + amoxicillin + clarithromycin + metronidazole.

Background: Antimicrobial resistance has decreased the worldwide eradication rates of common used triple therapy for Helicobacter pylori infection (less than 80%).

Objective: To determine the optimal pre-concommitant treatment length for rabeprazole based sequential-concomitant hybrid therapies for adults infected with Helicobacter pylori in Eastern Taiwan.

Design: Randomized, open-label, prospective controlled trial.

Patients: 231 patients with dyspepsia or peptic ulcers and infected by Helicobacter pylori.

Measurements: 13C-urea breath test, upper endoscopy, histologic evaluation, rapid urease test, bacterial culture, assessment of antibiotic resistance and CYP2C19 genotype of host.

Intervention: 231 patients with Helicobacter pylori infection are recruited and randomly assigned to receive one of the following therapeutic schemes: group 1, 14-days hybrid therapy: rabeprazole 20mg bid + amoxicillin 1g bid treated for 7 days, then rabeprazole 20mg bid + amoxicillin 1g bid + clarithromycin 0.5g bid + metronidazole 0.5g bid for other 7 days; group 2, 12-days hybrid therapy: rabeprazole 20mg bid + amoxicillin 1g bid treated for 5 days, then rabeprazole 20mg bid + amoxicillin 1g bid + clarithromycin 0.5g bid + metronidazole 0.5g bid for other 7 days; group 3, 10-days hybrid therapy: rabeprazole 20mg bid + amoxicillin 1g bid treated for 3 days, then rabeprazole 20mg bid + amoxicillin 1g bid + clarithromycin 0.5g bid + metronidazole 0.5g bid for other 7 days. Repeat upper endoscopy for histologic evaluation, rapid urease test or 13C-urea breath test after 4 week of treatment to assess the treatment result. The influence on the hybrid therapies of antibiotic resistance of Helicobacter pylori and CYP2C19 genotype of host were determined.

Expected results: The rabeprazole based sequential-concomitant therapies for eradication of Helicobacter pylori is very effective, and the outcome is not affected by antibiotic resistance of Helicobacter pylori and CYP2C19 genotype of host.

Inclusion Criteria:

• Patient proved with infection of H. pylori in gastric mucosa (at least two of four tests positive)

Exclusion Criteria:

• woman in breast feeding or pregnancy.
• allergy to drugs used in study.
• previously treated for H. pylori.
• intolerance to fructose, lactose.
• patients with hematologic, brain or spinal disorders
• patients under 20 years old
• patients under aspirin or clopidogrel
• patients with history of gastric cancer or gastric resection operation.