- Unsure if they stay in the area, have a history of allergic reactions to any antibiotic, lack adequate specimen for culture, phenylketonurics, women who are pregnant or unwilling to use 2 modern contraceptive methods during the 2-weeks they take the medications, with a history of heavy menses, anemic, history of peptic ulcer disease or had received Helicobacter eradication therapy or have abnormal lab results for kidney and liver functions tests. Will hold the enrollment for 4 weeks to those taking PPI, bismuth salts and antibiotics, and for 3 months since last blood transfusion or receiving intravenous iron preparations.