title: Meta-analysis: the efficacy, adverse events, and adherence related to first-line anti-Helicobacter pylori quadruple therapies.
abstract: BACKGROUND
  Owing to rising drug-resistant Helicobacter pylori infections, currently recommended proton-pump inhibitor-based triple therapies are losing their efficacy, and regimens efficacious in the presence of drug resistance are needed.
  
  
  OBJECTIVE
  To summarize the efficacy, safety and adherence of first-line quadruple H. pylori therapies in adults.
  
  
  METHODS
  Meta-regression models identified factors explaining variation in the efficacy of first-line quadruple therapies from 145 treatment arms. Estimates of average efficacy were calculated within homogeneous groups.
  
  
  RESULTS
  Quadruple therapy containing a gastric acid inhibitor, bismuth, metronidazole and tetracycline was enhanced when omeprazole was included, treatment duration lasted 10-14 days, and when therapy took place in the Netherlands, Hong Kong and Australia. Treatment efficacy decreased as the prevalence of metronidazole resistance increased. Even in areas with a high prevalence of metronidazole resistance, this quadruple regimen eradicated more than 85% of H. pylori infections when it contained omeprazole and was given for 10-14 days. Furthermore, in the presence of clarithromycin resistance, this quadruple regimen eradicated 90-100% of H. pylori infections, while the currently recommended triple therapy containing clarithromycin, amoxicillin and a proton-pump inhibitor eradicated only 25-61% (P < 0.001). Adherence and adverse events for quadruple therapy were similar to currently recommended triple therapies.
  
  
  CONCLUSIONS
  Guidelines should include quadruple therapy with a proton-pump inhibitor, a bismuth compound, metronidazole and tetracycline among recommended first-line anti-H. pylori therapies.
authors.affiliation: School of Public Health, University of Texas, Dallas Regional Campus, Dallas, TX, USA. lfischba@hsc.unt.edu
authors.forename: L A
authors.initials: LA
authors.lastname: Fischbach
authors.forename: S
authors.initials: S
authors.lastname: van Zanten
authors.forename: J
authors.initials: J
authors.lastname: Dickason
mesh_terms: D000863:Antacids / Q000627:therapeutic use; D001729:Bismuth / Q000627:therapeutic use; D024881:Drug Resistance, Bacterial; D004359:Drug Therapy, Combination / Q000627:therapeutic use*; D019983:Guideline Adherence; D016481:Helicobacter Infections / Q000188:drug therapy*; D016480:Helicobacter pylori; D006801:Humans; D008795:Metronidazole / Q000627:therapeutic use; D017410:Practice Guidelines as Topic; D013752:Tetracycline / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D000863:Antacids; D008795:Metronidazole; D013752:Tetracycline; D001729:Bismuth