Background: Levofloxacin has been proposed as an alternative to classic therapy in secondary resistance to Helicobacter pylori.
Aim: To evaluate primary and secondary resistance of H. pylori to levofloxacin, and to test the role of susceptibility test on the efficacy of levofloxacin-based triple therapy.
Methods: Eighty consecutive dyspeptic patients with positive (13)C-urea breath test never treated were randomly allocated into group A(1) (40 patients) and group B(1) (39 patients). Eighty-three patients already treated unsuccessfully with positive (13)C-urea breath test were divided into group A(2) (51 patients) and group B(2) (32 patients). Patients in group A(1) and group A(2) underwent upper gastrointestinal endoscopy for H. pylori susceptibility test to amoxicillin, clarithromycin, tinidazole, rifabutin, and levofloxacin. These patients were treated with levofloxacin (500 mg b.i.d.), amoxicillin (1 g b.i.d.) and esomeprazole (20 mg b.i.d.) for 10 days if sensitive to these two antibiotics. If H. pylori was found resistant to amoxicillin and/or levofloxacin the treatment was based on the indications of the susceptibility test. Patients in group B(1) and group B(2) were treated empirically with levofloxacin, amoxicillin, and esomeprazole at the same dose and duration as group A. All patients underwent (13)C-urea breath test 2 months after the end of therapy.
Results: The antibiotic resistance of H. pylori strains in group A(1) and group A(2) was (%): amoxicillin: 2.4, 10; clarithromycin: 21.9, 43.1; tinidazole: 31.7, 70; rifabutin: 2.4, 4; and levofloxacin: 9.7, 12.2, respectively. In group A(1) with susceptibility test-driven therapy, eradication was 97.2%, and in group B(1) with empirical treatment, 94.1% (n.s.). In group A(2) with susceptibility test, eradication was 97.5%, whereas in group B(2) with empirical treatment 81.2% (p < .01).
Conclusion: Primary and secondary resistance of H. pylori to levofloxacin is approximately 10% of the tested strains. The susceptibility test does not influence therapeutic outcome of triple therapy with amoxicillin and levofloxacin in patients never treated, while it is determinant for patients who were previously treated without success.