title: Primary resistance to antibiotics and its clinical impact on the efficacy of Helicobacter pylori lansoprazole-based triple therapies.
abstract: OBJECTIVE
  To evaluate Helicobacter pylori primary resistance and its clinical impact on the efficacy of two lansoprazole-based eradication triple therapies.
  
  
  METHODS
  H. pylori-positive patients (n=228) were randomized to receive one of the 1-week regimens: lansoprazole 30 mg, clarithromycin 500 mg and amoxicillin 1 g (LAC), or lansoprazole 30 mg, clarithromycin 500 mg and metronidazole 500 mg (LMC), each given twice daily. H. pylori status was assessed by 13C-urea breath test and culture at diagnosis and by 13C-urea breath test 6 weeks after therapy. Antibiotic susceptibility was determined by E-test (n=98).
  
  
  RESULTS
  The eradication rates with per protocol/ intention-to-treat analyses were: LAC (n=95/114) 83%/69% and LMC (n=96/114) 85%/72%. Primary resistance was 11% for clarithromycin, 41% for metronidazole and 0% for amoxicillin. Eradication in metronidazole-susceptible/-resistant strains was 85%/82% in LAC and 83%/63% in LMC. Significantly lower cure rates were observed in clarithromycin-resistant patients treated with LAC (95% vs. 0%, P < 0.001) and LMC (86% vs. 0%, P < 0.001).
  
  
  CONCLUSIONS
  One-week LAC and LMC are similarly effective therapies. Clarithromycin resistance significantly affected H. pylori eradication in both regimens.
authors.affiliation: Department of Internal Medicine, Taichung Veterans General Hospital, Taichung, Taiwan.
authors.forename: S K
authors.initials: SK
authors.lastname: Poon
authors.forename: C S
authors.initials: CS
authors.lastname: Chang
authors.forename: J
authors.initials: J
authors.lastname: Su
authors.forename: C H
authors.initials: CH
authors.lastname: Lai
authors.forename: C C
authors.initials: CC
authors.lastname: Yang
authors.forename: G H
authors.initials: GH
authors.lastname: Chen
authors.forename: W C
authors.initials: WC
authors.lastname: Wang
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000658:Amoxicillin / Q000627:therapeutic use; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000627:therapeutic use*; D017291:Clarithromycin / Q000627:therapeutic use; D004351:Drug Resistance; D004359:Drug Therapy, Combination; D005260:Female; D016481:Helicobacter Infections / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D064747:Lansoprazole; D008297:Male; D008795:Metronidazole / Q000627:therapeutic use; D008875:Middle Aged; D009853:Omeprazole / Q000031:analogs & derivatives* / Q000627:therapeutic use; D013624:Taiwan
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000900:Anti-Bacterial Agents; D064747:Lansoprazole; D008795:Metronidazole; D000658:Amoxicillin; D017291:Clarithromycin; D009853:Omeprazole