[Are proton pump inhibitors superior to H2 receptor antagonists within the scope of H. pylori eradication therapy? Meta analysis of current parallel group comparisons].

The combined treatment with acid lowering drugs and antibiotics is widely accepted for H. pylori-eradication therapy. There are, however, controversies regarding the influence of the acid lowering drug on H. pylori-eradication rates. Therefore, this meta-analysis aimed to assess the available parallel-group eradication studies with proton pump inhibitors and H2-receptor antagonists and to compare H. pylori-eradication rates for both classes of acid lowering drugs. METHODS. We performed a broad based medline search to retrieve all published treatment trails for H. pylori-infection. In addition, a manual search of the abstracts of major national and international meetings was conducted. In total seven publications of eight comparisons with a parallel group design comparing H2-receptor antagonists and proton pump inhibitors plus antibiotics with a total of 538 patients were identified. Non parametric tests were utilized to assess the influence of the acid lowering drug on eradication rates. Furthermore, logistic regression adjusting for duration of antibiotic treatment and the number of antibiotics was used to compare the different acid lowering drugs. RESULTS. All studies utilized omeprazole as the proton pump inhibitor with doses ranging from 20 mg/die to 2 x 20 mg/die. Ranitidine (with doses ranging from 2 x 150 mg/die to 2 x 300 mg/die) was used in six trials and nizatidine (2 x 300 mg/die) in one trial. H. pylori was successfully eradicated in 78.6% (95% 73.6-83.5) with the proton pump inhibitor and in 76.5% (95% Cl 71.4-81.5) in patients treated with the H2-receptor antagonists. Utilizing two antibiotics instead of one antibiotic significantly increased eradication rates by 16.1% (95% Cl 9.3-22.8, p < 0.001). However, neither in protocols with one nor in protocols with two antibiotics the eradication rates significantly differed for regimens using H2-receptor antagonists or proton pump inhibitors. CONCLUSION. H. pylori-eradication rates for treatment protocols with one or two antibiotics in combination with an acid lowering drug are not different for the proton pump inhibitors or h2-receptor antagonists. Therefore, the question whether H2-receptor antagonists or proton pump inhibitors should be used in combination with antibiotics for H. pylori eradication therapy is without clinical relevance.