To perform a meta-analysis of studies comparing twice daily, one-week triple therapy with a proton pump inhibitor, clarithromycin (C) and amoxycillin (A) (PCA) vs. those using proton pump inhibitor, clarithromycin and a nitroimidazole (N) (PCN) for H. pylori eradication.
Selection criteria: Comparative randomized trials of PCA vs. PCN were included. Data sources: PubMed database and abstracts from congresses until September 1999. Statistics: Meta-analysis was performed combining the Odds Ratios (OR) of the individual studies in a global OR (Peto method) both on an intention-to-treat (ITT) and on a per protocol (PP) basis.
Twenty-two studies fulfilled the inclusion criteria. Eighteen studies reported ITT and 20 PP analysis. Mean H. pylori eradication rates were 81% (95% CI: 79–83%) ITT, and 84% (82–86%) PP with PCA, and 81% (78–83%) ITT and 84% (82–86%) PP with PCN; the odds ratio for the effect of PCA vs. PCN was 1 (0.83–1.22) on an ITT, and 0.98 (0.8–1.2) on a PP basis. Subanalysis showed that mean H. pylori eradication efficacy with PC(250 b.d.)A was 81% (78–85%) ITT, vs. 86% (83–89%) with PC(250 b.d.)N. The odds ratio for this comparison was 0.68 (0.48–0.98). Finally, when comparing PC(500 b.d.)A against PC(250 b.d.)N ITT cure rates were 77% (74–80%), and 75% (72–78%) with an odds ratio of 1.18 (0.93–1.5).
Overall, one-week combination regimens of PCA and PCN present similar H. pylori eradication efficacy. Nevertheless, the PCN regimen obtains significantly better results when using low doses of C (250 mg b.d.).