Prevalence of Helicobacter pylori resistance after failure of first-line therapy. A systematic review.

There are no systematic data on the rates of antibiotic resistance after the failure of a first eradication treatment. The objective of this study was to determine the prevalence of secondary resistance to antibiotics by conducting a systematic review of studies evaluating the secondary resistance of Helicobacter pylori. We identified 31 studies (2,787 patients). Resistance was determined in 1,764 patients. A percentage of 99.1 of patients received clarithromycin as first-line treatment and 58.7% developed resistance. A percentage of 24.3 received metronidazole and 89.7% developed resistance. Secondary resistance to amoxicillin was extremely rare. Secondary resistance after first-line treatment was very common. These findings support the recommendation not to repeat clarithromycin or metronidazole after the failure of a first eradication treatment.