A practical approach to patients with refractory Helicobacter pylori infection, or who are re-infected after standard therapy

The vast majority of recurrences of Helicobacter pylori infection after app arent eradication are observed during the first year. Almost all of these e arly recurrences are due to recrudescence rather than reinfection by a new strain. After the first year, the recurrence rates approximate to the rate of natural acquisition of H. pylori infection. By contrast, in developing c ountries, higher rates of recurrence suggest a major role of real reinfecti on. Important predictive factors of H, pylori treatment success are compliance and bacterial susceptibility to antibiotics. The new 1-week triple therapie s, based on a proton pump inhibitor (PPI) and 2 antibiotics, lead to treatm ent discontinuation but rarely. If containing a nitroimidazole, their effic acy is reduced to 60 to 80% by pretreatment in vitro resistance. The preval ence of nitroimidazole resistance varies dependent on the geographical area , with rates over 50% in tropical re,regions. Resistance against macrolides hinders treatment success in 50 to 80% of patients. In the US, south-weste rn Europe and Japan the prevalence of macrolide resistance amounts to about 10%, in other countries about 3%. After failed treatment, acquired resistance is frequent. Testing for resist ance is recommended to facilitate the decision for an alternative triple th erapy or for quadruple therapy comprising bismuth, metronidazole, tetracycl ine and a PPI. It seems reasonable to increase the dose of PPI in a retreat ment regimen containing amoxicillin. Post-treatment double resistance again st nitroimidazoles and macrolides reduces the success of most of the curren tly evaluated retreatment regimens. To overcome double resistance, high dos e PPI plus amoxicillin is one approach, beside other experimental multidrug treatments.