Understanding treatment guidelines with bismuth and non-bismuth quadruple Helicobacter pylori eradication therapies.

INTRODUCTION: Recent Helicobacter pylori treatment guidelines recommend the 4-drug combinations bismuth quadruple therapy and concomitant therapy. Areas covered: We review antimicrobial therapy for H. pylori in the context of antimicrobial therapy in general and specifically in relation to good antimicrobial stewardship (defined as optimal selection, dose, and duration of an antimicrobial that results in the best clinical outcome for the treatment of infection, with minimal toxicity to the patient and minimal impact on subsequent resistance). Expert commentary: The lack of regional and local H. pylori susceptibility data prevents implementation of susceptibility-based antimicrobial therapy and forces compromises. Bismuth quadruple therapy employing at least 1,500 mg of metronidazole for 14 days is effective despite metronidazole resistance. The main drawback is side effects causing reduced adherence. Versions where amoxicillin replaces metronidazole or tetracycline also appear effective. It is likely that bismuth quadruple therapy can be simplified by giving bismuth and possibly tetracycline b.i.d., possibly with fewer side effects. Concomitant therapy (a proton pump inhibitor, metronidazole, clarithromycin, amoxicillin) is ineffective with dual clarithromycin-metronidazole resistance and all patients receive at least one unnecessary antibiotic thus promoting antimicrobial resistance worldwide. Concomitant therapy should be abandoned when susceptibility testing becomes widespread or an alternate becomes available.