Optimal duration of therapy combining ranitidine bismuth citrate with clarithromycin and metronidazole in the eradication of Helicobacter pylori infection

Background: Ranitidine bismuth citrate (RBC) co-prescribed with clarithromycin and metronidazole for 1 week has been shown to be an effective eradicating regimen for Helicobacter pylori. Aim: To determine the optimal duration of this regimen. Methods: A series of 165 dyspeptic patients were recruited for this randomized, open, parallel-group study. They were subdivided into three groups receiving RBC 400 mg b.d. plus clarithromycin 250 mg b.d, and metronidazole 500 mg b.d. for three different periods (4, 7 and 10 days). H. pylori infection was assessed by the concomitant positivity of CLO-test and histology performed at the pre-entry endoscopy, The bacterium was considered eradicated on the basis of a negative C-13-urea breath test performed at least 28 days after the completion of treatment. Results: The three subgroups were well matched and 16 patients dropped out of the study for many reasons (six in the 4-day, five in the 7-day and five in the 10-day treatment regimens). Intention-to-treat cure rates were 60%, 84% and 85%, and the per-protocol rates 67%, 92% and 94% in the 4-day, 7-day and 10-day treatment regimens, respectively, There was a significant difference, P = 0.003-0.006 on intention-to-treat and P = 0.001-0.002, on per protocol analysis between the 4-day and the 7-day and the 4-day and the 10-day periods, respectively, The 7-day and 10-day periods did not differ from each other. Side-effects were reported in 9%, 14% and 20% of the 4-, 7- and 10-day regimens. They led to stopping treatment in four cases (one in the 7-day and three in the 10-day period). There was no statistical difference among them. Conclusions: Reducing the duration of RBC-based triple therapy to 4 days provides a low and unacceptable rate of H, pylori eradication. As there is no difference between 7 and 10 days of treatment, 1 week represents the optimal time period for this kind of treatment, based on RBC plus two antibiotics.