Antimicrobial Susceptibility-Guided Therapy Versus Empirical Concomitant Therapy for Eradication of Helicobacter pylori in a Region with High Rate of Clarithromycin Resistance

Background: Nonbismuth quadruple (concomitant) regimen is recommended for first-line empirical Helicobacter pylori (HP) eradication treatment when clarithromycin resistance is more than 15-20%. Our objective was to evaluate the efficacy and tolerability of concomitant versus antimicrobial susceptibility-guided treatment in an area with high rates of clarithromycin resistance. Methods: Three hundred consecutive HP-infected patients received antimicrobial susceptibility-guided therapy or empirical concomitant therapy for 10 days. The concomitant regimen was omeprazole (20 mg/12 hour), amoxicillin (1 g/12 hour), clarithromycin (500 mg/12 hour), and metronidazole (500 mg/12 hour) (OACM). Patients diagnosed by culture received one of three combinations of antibiotics based on susceptibility results: omeprazole, amoxicillin, and clarithromycin (OAC); omeprazole, amoxicillin, and levo-floxacin (OAL); or omeprazole, amoxicillin, and metronidazole (OAM), at the aforementioned doses (and 500 mg/12 hour in the case of levofloxacin). Eradication was confirmed with a C-13 urea breath test, 6 weeks after treatment. Adverse events and adherence were assessed with questionnaires and reviewing medication sachets. Results: The mean age was 50 years, 59% were women, and 14% had peptic ulcers. Concomitant and antimicrobial susceptibility-guided eradication rates were, respectively, 87% and 94% by intention-to-treat (p =.08) and 89% and 95% (p = .08) per protocol per-protocol analysis. Adverse effects were reported in 31% of patients on OACM and 15% of those on susceptibility- guided therapy (p < .05). Conclusions: For HP eradication in a region with high rates of multiple drug resistance, antimicrobial susceptibility-guided therapy is more effective than empirical concomitant therapy.