Sequential versus concomitant therapy for treatment of Helicobacter pylori infection: an updated systematic review and meta-analysis.

The efficacy of concomitant therapy was duration dependent, and 10-day concomitant therapy was superior to 10-day sequential therapy. Compared to sequential therapy, concomitant therapy was more efficacious for metronidazole-resistant strains and metronidazole plus clarithromycin-resistant strains. However, diarrhea was more frequent with concomitant therapy than with sequential therapy.