Causes of failure of eradication of Helicobacter pylori

摘要

Eradication of Helicobacter pylori from the gastric and duodenal mucosa of infected patients is the most important goal in the management of peptic ulcer disease and other conditions associated with H pylori. The survival capabilities of H pylori in the stomach make it difficult to eradicate, and effective treatment requires multidrug regimens consisting of two antibiotics (usually selected from clarithromycin, metro-nidazole, amoxicillin, and tetracycline), combined with acid suppressants and bismuth compounds. A significant proportion of patients do not respond to treatment, and adverse treatment outcome is associated with advanced age, smoking, high intragastric bacterial load before treatment, bacterial genotype, and host genetic polymorphisms of the cytochrome-P450 isoenzymes that are specifically involved in the metabolism of proton pump inhibitors. Adherence to the drug regimen is particularly important for successful eradication of infection and can be improved by education of patients and programmes to improve compliance. But as in many other infectious diseases, antibiotic resistance is the major cause of treatment failure. Meta-analyses have established beyond doubt that resistance to either the macrolide or 5-mtroimidazole component of the regimen is an important predictor of eradication failure. The extent to which resistance compromises efficacy is related to the other components of the drug regimen and is less pronounced for metronidazole than clarithromycin.