From the profiles of antibiotic susceptibility data following eradication therapy, tetracycline, amoxicillin and levofloxacin are all good candidates of antibiotics used in the rescue treatment.

The H pylori-infected adult patients with failure of standard triple therapy and H pylori-infected adult patients with failure of non-bismuth quadruple therapy are randomly assigned to either TL quadruple therapy (esomeprazole-bismuth-tetracycline-levofloxacin regimen) or AL quadruple therapy (esomeprazole-bismuth-amoxicillin-levofloxacin regimen) for 10 days. Repeated endoscopy with rapid urease test, histological examination and culture or urea breath tests is performed at six weeks after the end of anti-H pylori therapy.

Inclusion Criteria:

• Consecutive H pylori-infected outpatients, at least 20 years of age with failure of first-line eradication treatments (standard triple, non-bismuth quadruple and bismuth quadruple therapies)

Exclusion Criteria:

• previous allergic reactions to the study medications,
• history of gastrectomy,
• use of antibiotics within the previous 4 weeks,
• pregnant or lactating women,
• coexistence of serious concomitant illness (for example, decompensated liver cirrhosis, uremia, and malignancy).