Rescue Therapy for Helicobacter pylori.

Up to 35% of patients infected with Helicobacter pylori fail to respond to standard anti-H. pylori therapy. With the rising prevalence antimicrobial resistance, the failure rates of conventional proton pump inhibitor-containing triple therapy are expected to increase. Pretreatment antibiotic resistance testing should be done whenever possible to allow for tailoring of the treatment regimens. The data on second-line or rescue therapy are limited and usually are subjected to various biases and confounding factors. Switching between clarithromycin and metronidazole should be considered if repeated courses of proton pump inhibitor-containing triple therapy are used as second-line therapy in the absence of antimicrobial sensitivity testing. The prolongation of therapy duration with proton pump inhibitor, amoxicillin, and clarithromycin is ineffective for clarithromycin-resistant strains. The bismuth-containing quadruple therapy is the best salvage treatment in the absence of pretreatment antibiotic susceptibility. Furazolidone quadruple therapy (where available) and rifabutin triple therapy are salvage therapies of last resort. If these regimens fail, culture and susceptibility testing is required.