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

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