Daily Four Times or Two Times Usage of PPI and Amoxicillin for the First or Second Line H. Pylori Eradication

The hypothesis and plan of the current study are: 1. One induction phase of high dose PPI before eradication will increase intragastric pH and induce H. pylori into an active replicative status. Active replicative status will enhance the bactericidal effect of amoxicillin. Rabeprazole (20 mg) four times per day (qid) for 3 days will be used for induction in this study. 2. High dose PPI will provide adequate plasma concentration irrespective of the CYP2C19 genotype of the population. Here rabeprazole (20 mg) qid will be applied as high dose PPI. 3. High frequent amoxicillin usage (500 mg, qid) will maintain plasma concentration above the MIC. Amoxicillin (500 mg) qid will be described for total 14 days. 4. In the rescue therapy, add levofloxacin on high dose dual therapy will increase the eradication rate than single high dose dual therapy. A combination of levofloxacin and high dose dual therapy will also have a better eradication rate than the common used levofloxacin based triple therapy.