Inefficacy of Triple Therapy and Comparison of Two Different Bismuth-containing Quadruple Regimens as a Firstline Treatment Option for Helicobacter pylori

Background/Aim:Increasing resistance of Helicobacter pylori to antimicrobials necessitated the development of new regimens and the modification of existing regimens. The present study aimed to compare the efficacy of two bismuth-containing quadruple regimens–one including clarithromycin (C) instead of metronidazole (M) and triple therapy.Results:At per-protocol analysis, the eradication rates were 64.7% (95% confidence interval 60.4–68.7) with the triple therapy (n = 504), 95.4% (95% confidence interval 91.5–99.4) with the bismuth group C (n = 501), and 93.9% (95% confidence interval 89.7–98.7) with the bismuth group M (n = 505). The eradication rates were similar between the two bismuth groups (P > 0.05) but significantly greater than that of the triple therapy (P < 0.05).Conclusion:In our study, both of the bismuth-containing quadruple therapies reached high eradication rates, whereas triple therapy was shown to be ineffective. Moreover, clarithromycin may also be a component of bismuth-containing quadruple therapy.Key Words: Bismuth, clarithromycin, eradication, Helicobacter pylori, metronidazoleHelicobacter pylori infection is a worldwide problem. Eighty percent of the population in developing countries and 20%–50% of the population in the developed countries are estimated to carry this pathogen.[1,2,3] The ultimate clinical manifestations of H. pylori infection include gastric and duodenal ulcer, gastric mucosa–associated lymphoid tissue lymphoma, and adenocarcinoma.[4,5] H. pylori eradication remains a challenge for the physicians, since no firstline regimen is able to cure the infection in all treated patients due to antibiotic resistance. The efficacy of standard triple therapy has decreased recently and is less than the 80% rate aimed for at the beginning.[5,6,7,8] The background rate of clarithromycin resistance is critically important as its presence negatively impacts the efficacy of standard triple therapy.[9] For this reason bismuth-containing quadruple therapies are recommended for firstline empirical treatment in areas of high clarithromycin resistance (>15%–20%) according to Maastricht IV consensus report.[8]It is known that resistance to metronidazole can be partially overcome by increased dose and duration of treatment.[10] This multicenter study aimed to perform a comparison among two bismuth-containing quadruple therapies—one including clarithromycin (C) instead of metronidazole (M) and triple therapy for H. pylori eradication in dyspeptic patients.