The purpose of this study is to compare the eradication efficacy of 10-day triple therapy with 10-day sequential therapy with tetracycline or metronidazole.

Background: Antimicrobial resistance has decreased eradication rates for Helicobacter pylori infection worldwide.

Objective: To determine whether sequential treatment eradicates H. pylori infection better than standard triple-drug therapy for adults with dyspepsia or peptic ulcers in Taiwanese people.

Design: Randomized, single-blind, prospective controlled trial. Setting: A large tertiary referral hospital in eastern Taiwan. Patients: 450 patients with dyspepsia or peptic ulcers and infected by H. 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: 450 patients with H. pylori infection are randomly assigned to receive one of the following therapeutic schemes: group A (5RA5RCT): rabeprazole (20 mg bid) plus amoxicillin (1 g bid) for 5 days, followed by rabeprazole (20 mg bid) plus clarithromycin (500 mg bid) and tetracycline (1g bid) for a further 5 days; group B (5RA5RCM): rabeprazole (20 mg bid) plus amoxicillin (1 g bid) for 5 days, followed by rabeprazole (20 mg bid) plus clarithromycin (500 mg bid) and metronidazole (500mg bid) for a further 5 days; group C as control: rabeprazole (20 mg bid) plus amoxicillin (1 g bid) and clarithromycin (500 mg bid.) for 10 days.

Inclusion Criteria:

• patient proved with infection of H. pylori in gastric mucosa
• adult with signed inform consent

Exclusion Criteria:

• woman in breast feeding or pregnancy.
• allergy to drugs used in study.
• three months without use of any antibiotic agents.
• patients under 20 years old.