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

Helicobacter, 04/13/2012

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.


  • 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.

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