title: Quadruple therapy is effective for eradicating Helicobacter pylori after failure of triple proton-pump inhibitor-based therapy: a detailed, prospective analysis of 21 consecutive cases.
abstract: BACKGROUND
  Data regarding the effectiveness of second-line treatment of Helicobacter pylori infection are limited, especially if microbiological studies are considered.
  
  
  METHODS
  We conducted a prospective, uncontrolled study of a consecutive series of 21 peptic ulcer patients with failure of 1-week lansoprazole, amoxicillin, and clarithromycin. H. pylori status was evaluated by urease test, histology, culture, and urea breath test. Susceptibility to amoxicillin, clarithromycin, and metronidazole was studied by E-test. Cure of infection was defined as negative results from endoscopy-based tests 1 month after treatment and negative results from a urea breath test at 2 months. Treatment consisted of a 1-week combination of lansoprazole (30 mg bid), tetracycline (500 mg qid), metronidazole (500 mg tid), and bismuth subcitrate (120 mg qid).
  
  
  RESULTS
  H. pylori was resistant to metronidazole in three cases, to clarithromycin in three cases, and to both clarithromycin and metroinidazole in an additional three patients. No resistance to amoxicillin was found. Eradication was obtained in 20 cases (95.2% confidence interval [CI], 76.2-99.9). The only patient in whom infection was not eradicated harbored a metronidazole-resistant (minimum inhibitory concentration > 32 micrograms/ml) strain. No significant side effects were reported.
  
  
  CONCLUSIONS
  Quadruple therapy obtains a high eradication rate even in patients with clarithromycin- and metronidazole-resistant strains. Further randomized and controlled studies are warranted and are urgently needed.
authors.affiliation: Digestive Disease Unit, Hospital San Jorge, Huesca, Spain.
authors.forename: F
authors.initials: F
authors.lastname: Gomollón
authors.forename: J A
authors.initials: JA
authors.lastname: Ducóns
authors.forename: M
authors.initials: M
authors.lastname: Ferrero
authors.forename: J
authors.initials: J
authors.lastname: García Cabezudo
authors.forename: R
authors.initials: R
authors.lastname: Guirao
authors.forename: M A
authors.initials: MA
authors.lastname: Simón
authors.forename: M
authors.initials: M
authors.lastname: Montoro
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000328:Adult; D000368:Aged; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use*; D017291:Clarithromycin / Q000494:pharmacology / Q000627:therapeutic use; D004352:Drug Resistance, Microbial; D004359:Drug Therapy, Combination; D005260:Female; D016481:Helicobacter Infections / Q000150:complications / Q000188:drug therapy* / Q000382:microbiology*; D016480:Helicobacter pylori / Q000187:drug effects* / Q000302:isolation & purification; D006801:Humans; D064747:Lansoprazole; D008297:Male; D008795:Metronidazole / Q000494:pharmacology / Q000627:therapeutic use; D008826:Microbial Sensitivity Tests; D008875:Middle Aged; D009853:Omeprazole / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D010437:Peptic Ulcer / Q000188:drug therapy / Q000382:microbiology; D011446:Prospective Studies; D054328:Proton Pump Inhibitors; D016896:Treatment Outcome
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000900:Anti-Bacterial Agents; D054328:Proton Pump Inhibitors; D064747:Lansoprazole; D008795:Metronidazole; D017291:Clarithromycin; D009853:Omeprazole