Israel Medical Association Journal

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.

Background: Antimicrobial resistance is the main determinant for Helicobacter pylori treatment failure. Regional antimicrobial susceptibility testing is essential for appropriate antibiotic selection to achieve high eradication rates.

Objectives: To assess primary and secondary H. pylori resistance in isolates recovered from Israeli naïve and treatment failures. To identify predictors of resistance.

Methods: In this retrospective study, in vitro activity of isolated H. pylori in Israel was tested against metronidazole, clarithromycin, tetracycline, amoxicillin, and levofloxacin in 128 isolates: 106 from treatment failures and 22 from naïve untreated patients. The minimal inhibitory concentration values were determined according to the Etest instructions. Treatment failures previously failed at least one treatment regimen.

Results: No resistance to amoxicillin and tetracycline was detected. Resistance to metronidazole and clarithromycin was high in H. pylori isolates both from treated and untreated patients: 68.9%, 68.2% for metronidazole (P = 0.95); 53.8%, 59.1% for clarithromycin (P = 0.64), respectively. Dual resistance to clarithromycin and metronidazole was seen in 45.3% and 50%, respectively (P = 0.68). Resistance to levofloxacin was detected in two (1.9%) isolates from treated patients. Simultaneous resistance to clarithromycin, metronidazole, and levofloxacin was seen in an isolate from a treated patient. Age was the only predictor of resistance to metronidazole and clarithromycin.

Conclusion: The resistance rates to both single and dual metronidazole and clarithromycin in isolates recovered from both Israeli naïve and treated patients is high. Low resistance renders levofloxacin an attractive option for second or third line treatment. Therapeutic outcome would benefit from susceptibility testing after treatment failure.