From January @ to December @ , consecutive H.pylori-infected patients were randomly assigned to receive either sequential therapy ( a @-day dual therapy with pantoprazole plus amoxicillin , followed by a @-day triple therapy with pantoprazole plus clarithromycin and metronidazole ) or reverse sequential therapy ( a @-day triple therapy with pantoprazole plus clarithromycin and metronidazole , followed by a @-day dual therapy with pantoprazole plus amoxicillin ) .