Editing Peptic ulcer disease (section)

===Eradication therapy===
Once the diagnosis of ''H. pylori'' is confirmed, the first-line treatment would be a triple regimen in which [[pantoprazole]] and [[clarithromycin]] are combined with either [[amoxicillin]] or [[metronidazole]]. This treatment regimen can be given for 7–14 days. However, its effectiveness in eradicating ''H. pylori'' has been reducing from 90% to 70%. However, the rate of eradication can be increased by doubling the dosage of pantoprazole or increasing the duration of treatment to 14 days. Quadruple therapy (pantoprazole, clarithromycin, amoxicillin, and metronidazole) can also be used. The quadruple therapy can achieve an eradication rate of 90%. If the clarithromycin resistance rate is higher than 15% in an area, the usage of clarithromycin should be abandoned. Instead, [[bismuth]]-containing quadruple therapy can be used (pantoprazole, bismuth citrate, [[tetracycline]], and metronidazole) for 14 days. The bismuth therapy can also achieve an eradication rate of 90% and can be used as second-line therapy when the first-line triple-regimen therapy has failed.