Levofloxacin or Clarithromycin-based quadruple regimens: what is the best alternative as first-line treatment for Helicobacter pylori eradication in a country with high resistance rates for both antibiotics?

Background: Helicobacter pylori eradication rates in Portugal are declining, due to increased resistance of this bacterium to antimicrobial agents, especially Clarithromycin. Quadruple Levofloxacin-containing regimens could be an option for first-line treatment, but its efficacy should be evaluated as fluoroquinolone resistance is rapidly increasing. Our aim was to compare the efficacy of Clarithromycin and Levofloxacin-based sequential quadruple therapies as first-line treatment options and determine factors associated with treatment failure. Methods: A total of 200 Helicobacter pylori infected patients were retrospectively included (female 57.5%; average age: 53.2 +/- 15.7) and received either 10-day sequential therapy (Proton-Pump Inhibitor + Amoxicillin 1 g bid for 5 days and Proton-Pump Inhibitor + Clarithromycin 500 mg + Metronidazole/Tinidazole 500 mg bid/tid in the following 5 days; group A) or a 10-day modified sequential therapy with Levofloxacin 500 mg id instead of Clarithromycin (group B). Eradication was confirmed with urea breath test. Variables that could influence success rate were analyzed. Results: There were no differences between groups in terms of gender, age, smoking habits and indications for treatment. The eradication rate obtained with Clarithromycin-based sequential treatment was significantly higher than with Levofloxacin-based therapy (90%, CI95%: 84-96% vs. 79%, CI95%: 71-87%, p = 0.001). Using full-dose proton-pump inhibitor and high-dose Metronidazole in group A, and full-dose proton-pump inhibitor and prescription from a Gastroenterologist in group B were associated with eradication success. Conclusions: Ten-day Levofloxacin-based sequential treatment achieved inadequate efficacy rate (< 80%) and should not be adopted as first-line therapy. Standard sequential therapy showed significantly better results in this naive population. Using full-dose proton-pump inhibitor and higher doses of Metronidazole is essential to achieve such results.