title: Seven-Day Bismuth-based Quadruple Therapy as an Initial Treatment for Helicobacter pylori Infection in a High Metronidazole Resistant Area.
abstract: BACKGROUND
  The prevalence of metronidazole-resistant H. pylori is almost 50% in Thailand which severely limits the use of this drug for eradication therapy. The aims of this study were to evaluate the efficacy and safety profiles of 7-day bismuth-based quadruple therapy including metronidazole as an initial treatment for H. pylori infection in a high metronidazole resistance area.
  
  
  METHODS
  This study was performed at Thammasat University Hospital and King Chulalongkorn Memorial Hospital during January 2009 to October 2010. Patients with non-ulcer dyspepsia (NUD) with active H. pylori infection were assigned to receive seven days of quadruple therapy (pantoprazole 40 mg bid, bismuth subsalicylate 1,048 mg bid, amoxicillin 1 gm bid and metronidazole 400 mg tid). H. pylori infection was defined as positive H. pylori culture or two positive tests (rapid urease test and histology). Antibiotic susceptibility test for metronidazole by Epsilometer test (E-test) was performed in all positive cultures. At least four weeks after treatment, 13C urea breath test (13C-UBT) was performed to confirm H. pylori eradication.
  
  
  RESULTS
  A total of 114 patients were enrolled in this study, 50 males and 64 females with a mean age of 49.8 years. All 114 patients had a diagnosis of NUD. Overall eradication as confirmed by negative 13C-UBT was achieved in 94 out of 114 patients (82.5%). 44 patients had positive cultures and success for E-test. In vitro metronidazole resistance was observed in 22/44 (50%) patients. Eradication rate in patients with metronidazole resistant strains was 16/22 (72.7%) and 20/22 (90.1%) with metronidazole sensitive strains (72.7% vs 90.1%, p-value=0.12; OR=3.75 [95%CI=0.6-31.5]). Minor adverse reactions included nausea, bitter taste, diarrhea and black stools but none of the patients dropped out from the study.
  
  
  CONCLUSIONS
  Initial treatment with 7-day bismuth-based quadruple therapy including metronidazole, amoxycillin and pantoprazole is highly effective and well tolerated for metronidazole-sensitive H. pylori infections. However, the efficacy markedly decline with metronidazole resistance. Longer duration of this regimen might be required to improve the eradication rate and larger multi-center studies are needed to confirm this hypothesis.
authors: Gastroenterology Unit, Department of Medicine, Thammasat University Hospital, Pathumthani, Thailand E-mail : Vilaichone@hotmail.co.th.
authors: Ratha-korn
authors: RK
authors: Vilaichone
authors: Hatainuch
authors: H
authors: Prapitpaiboon
authors: Pornpen
authors: P
authors: Gamnarai
authors: Juraiwan
authors: J
authors: Namtanee
authors: Arti
authors: A
authors: Wongcha-um
authors: Supakarn
authors: S
authors: Chaithongrat
authors: Varocha
authors: V
authors: Mahachai
mesh_terms: D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001729:Bismuth / Q000627:therapeutic use*; D001944:Breath Tests; D024881:Drug Resistance, Bacterial / Q000187:drug effects*; D004359:Drug Therapy, Combination; D005260:Female; D005500:Follow-Up Studies; D016481:Helicobacter Infections / Q000188:drug therapy* / Q000453:epidemiology / Q000382:microbiology; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000494:pharmacology*; D008875:Middle Aged; D009942:Organometallic Compounds / Q000627:therapeutic use*; D011379:Prognosis; D012459:Salicylates / Q000627:therapeutic use*; D013785:Thailand / Q000453:epidemiology
chemical_list: D000900:Anti-Bacterial Agents; D009942:Organometallic Compounds; D012459:Salicylates; D008795:Metronidazole; C015715:bismuth subsalicylate; D001729:Bismuth