Nonbismuth quadruple (concomitant) therapy: empirical and tailored efficacy versus standard triple therapy for clarithromycin-susceptible Helicobacter pylori and versus sequential therapy for clarithromycin-resistant strains

Abstract

Background: Using quadruple clarithromycin-containing regimens for Helicobacter pylori eradication is controversial with high rates of macrolide resistance.

Aim: To evaluate antibiotic resistance rates and the efficacy of empirical and tailored nonbismuth quadruple (concomitant) therapy in a setting with cure rates <80% for triple and sequential therapies.

Methods: 209 consecutive naive H. pylori-positive patients without susceptibility testing were empirically treated with 10-day concomitant therapy (proton pump inhibitors (PPI), amoxicillin 1 g, clarithromycin 500 mg, and metronidazole 500 mg; all drugs b.i.d.). Simultaneously, 89 patients with positive H. pylori culture were randomized to receive triple versus concomitant therapy for clarithromycin-susceptible H. pylori, and sequential versus concomitant therapy for clarithromycin-resistant strains. Eradication was confirmed with ¹³C-urea breath test or histology 8 weeks after completion of treatment.

Results: Per-protocol (PP) and intention-to-treat eradication rates after empirical concomitant therapy without susceptibility testing were 89% (95%CI:84-93%) and 87% (83-92%). Antibiotic resistance rates were: clarithromycin, 20%; metronidazole, 34%; and both clarithromycin and metronidazole, 10%. Regarding clarithromycin-susceptible H. pylori, concomitant therapy was significantly better than triple therapy by per protocol [92% (82-100%) vs 74% (58-91%), p = 0.05] and by intention to treat [92% (82-100%) vs 70% (57-90%), p = 0.02]. As for antibiotic-resistant strains, eradication rates for concomitant and sequential therapies were 100% (5/5) vs 75% (3/4), for clarithromycin-resistant/metronidazole-susceptible strains and 75% (3/4) vs 60% (3/5) for dual-resistant strains.

Conclusions: Empirical 10-day concomitant therapy achieves good eradication rates, close to 90%, in settings with multiresistant H. pylori strains. Tailored concomitant therapy is significantly superior to triple therapy for clarithromycin-susceptible H. pylori and at least as effective as sequential therapy for resistant strains.