- The patients who proved a failure of 1st eradication of H. pylori with Proton pump inhibitor based triple therapy (PPI bid + amoxacillin 1g b.i.d + Clarithromycin 500 mg b.i.d) or sequential therapy (initial 5-day therapy with a combination of PPI b.i.d and amoxicillin 1g b.i.d, followed by 5 days of PPI b.i.d., clarithromycin 500mg b.i.d., and metronidazole 500mg t.i.d) following three methods