One-hundred and sixty patients with dyspeptic complaints and nave Helicobacter pylori infection were randomized into four groups : 41 patients received standard 14-day quadruple treatment ( STD ) ( Rabeprazole 20mg-bid , bismuth subcitrate ( 120 mg-qid ) , Tetracycline 500 mg-qid , Metronidazole 500 mg-tid ) for 2 weeks .