Effectiveness of treatments against Helicobacter pylori according to resistance to clarithromycin: data from the European registry on Helicobacter pylori management (HP-EUREG)

Introduction: Antibiotic resistance is the main factor influencing the ef-ficacy of treatments to eradicate the infection by Helicobacter pylori (H. pylori). The treatments including clarithromycin are the most frequently used in first-line ; however, the bacterial resistance to clarithromycin in treatment-naïve patients in Europe is, overall, >20%.Aims & Methods: To assess the effectiveness of first-line H. pylori treat- ments in Europe according to the resistance to clarithromycin.Non-interventional, prospective, multicenter, international European re-gistry on the management of H. pylori (Hp-EuReg). All culture-diagnosed infected adult patients were registered at AEG-REDCap e-CRF from 2013 to 2021. Per-protocol (PP) analysis was performed based on the presence or absence of bacterial resistance to clarithromycin in treatment-naïve pati-ents. The data was subject to quality control.Results: In total, 2, 479 culture-naïve patients were included. Of these, 627 (25%) reported resistance to clarithromycin. The eradication rate with the standard triple therapy (PPI+clarithromycin+amoxicillin) in patients susceptible to clarithromycin was 92% (424/460). The eradication rate in these clarithromycin-susceptible patients was higher both with the con-comitant regimen (PPI+clarithromycin+amoxicillin+metronidazole) and with the sequential treatment with tinidazole (95%, 882/929), and also with the bismuth quadruple regimen (PPI+bismuth+tetracycline+metronidazole) as single capsule (100%, 67/67) (p