Background: The antibiotic resistance profile of Helicobacter pylori (H. pylori) is constantly changing. Up-to-date and reliable data for the effectiveness of first-line H. pylori treatment protocols are necessary to provide evidence-based best-practice guidelines.

Objectives: To determine the effectiveness, compliance and safety of first-line treatment for H. pylori in Israel.

Methods: An observational, prospective, multicenter study was conducted in tertiary referral centers in Israel, as part of the European registry on H. pylori management (Hp-EuReg). H. pylori-infected patients were included from 2013 to March 2020. Data collected included demographics, clinical data, diagnostic tests, previous eradication attempts, current treatment, compliance, adverse events, and treatment outcome result.

Results: In total, 242 patients were registered, including 121 (50%) who received first-line therapy, 41% of these individuals received clarithromycin based triple therapy and 58.9% received a four-drug regimen. The overall effectiveness of first-line therapy was 85% and 86% by modified intention-to-treat and per protocol analyses, respectively. The effectiveness of both sequential and concomitant therapies was 100% while clarithromycin-based triple therapy achieved an eradication rate of 79%. Treatment eradication was higher among patients who received high dose proton pump inhibitor (PPI) compared to those treated with low dose PPI (100% vs. 81.5% respectively, P < 0.01). No difference in treatment effectiveness was found between 7-, 10-, and 14-day treatment.

Conclusions: The effectiveness of clarithromycin-based triple therapy is suboptimal. First-line treatment of H. pylori infection should consist of four drugs, including high dose PPI, according to international guidelines.