title: Influence of metronidazole resistance on efficacy of quadruple therapy for Helicobacter pylori eradication.
abstract: BACKGROUND
  Metronidazole-containing eradication therapies are less effective for metronidazole resistant Helicobacter pylori. Although early data suggested improvement of the efficacy of bismuth triple therapy after the addition of acid suppressives, these findings were based on studies with small numbers of patients, incomplete post-eradication follow up, or omission of pretreatment susceptibility testing.
  
  
  OBJECTIVE
  To study the efficacy of quadruple therapy in the Amsterdam area, where the efficacy of bismuth triple therapy has been proved to be affected by metronidazole resistance.
  
  
  METHODS
  Eighty two consecutive dyspeptic H pylori positive patients with either metronidazole susceptible (group I) or metronidazole resistant H pylori strains (group II) received quadruple therapy for one week: omeprazole 20 mg twice daily; colloidal bismuth subcitrate 120 mg four times a day; tetracycline 500 mg four times a day; metronidazole 500 mg three times a day. Susceptibility to metronidazole was determined by the E-test.
  
  
  RESULTS
  Intention to treat analysis showed that H pylori infection had been cured in 42/43 patients (98%) in group I and 32/39 patients (82%) in group II (p = 0.02).
  
  
  CONCLUSIONS
  The efficacy of quadruple therapy is significantly impaired in patients infected with metronidazole resistant H pylori. Therefore a non-metronidazole-containing regimen should preferably be used in areas known to have a high prevalence of pretreatment metronidazole resistance.
authors.affiliation: Department of Gastroenterology, Academic Medical Centre, Amsterdam, The Netherlands.
authors.forename: R W
authors.initials: RW
authors.lastname: van der Hulst
authors.forename: A
authors.initials: A
authors.lastname: van der Ende
authors.forename: A
authors.initials: A
authors.lastname: Homan
authors.forename: P
authors.initials: P
authors.lastname: Roorda
authors.forename: J
authors.initials: J
authors.lastname: Dankert
authors.forename: G N
authors.initials: GN
authors.lastname: Tytgat
mesh_terms: D000328:Adult; D000900:Anti-Bacterial Agents / Q000627:therapeutic use; D000897:Anti-Ulcer Agents / Q000627:therapeutic use; D000994:Antitrichomonal Agents / Q000627:therapeutic use*; D004352:Drug Resistance, Microbial; D004359:Drug Therapy, Combination; D005260:Female; D016481:Helicobacter Infections / Q000188:drug therapy*; D016480:Helicobacter pylori; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000627:therapeutic use*; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009853:Omeprazole / Q000627:therapeutic use; D009942:Organometallic Compounds / Q000627:therapeutic use; D018579:Patient Selection; D013752:Tetracycline / Q000627:therapeutic use; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D000897:Anti-Ulcer Agents; D000994:Antitrichomonal Agents; D009942:Organometallic Compounds; D008795:Metronidazole; D013752:Tetracycline; C002791:bismuth tripotassium dicitrate; D009853:Omeprazole