title: Clarithromycin Versus Metronidazole as First-line Helicobacter pylori Eradication: A Multicenter, Prospective, Randomized Controlled Study in Japan.
abstract: BACKGROUND
  Helicobacter pylori eradication rates achieved with a first-line regimen of clarithromycin (CLR) combined with amoxicillin (AMX) and a proton pump inhibitor have recently fallen to ≤80% because of the increasing incidence of CLR resistance in Japan. This randomized multicenter trial aimed to compare the eradication success of 2 first-line triple therapy regimens: rabeprazole, amoxicillin, and clarithromycin (RAC) versus rabeprazole, amoxicillin, and metronidazole (RAM).
  
  
  METHODS
  A total of 124 consecutive patients infected with H. pylori were randomized into one of two 7-day therapeutic regimens: RAC (n=60) or RAM (n=64). Eradication was confirmed by the C-urea breath test. Adverse effects were also assessed.
  
  
  RESULTS
  Intention-to-treat and per protocol H. pylori eradication rates were 73.3%/77.2% in the RAC group and 90.6%/93.5% in the RAM group. The eradication rate of RAM therapy was significantly higher than that of RAC therapy. CLR, metronidazole, and AMX resistance was found in 36.2%, 2.1%, and 0% of patients, respectively. In addition, no relevant differences in adverse effects were observed.
  
  
  CONCLUSIONS
  Metronidazole-based therapy (RAM) was superior to standard CLR-based therapy (RAC) for first-line H. pylori eradication. This reflects the progressive increase in CLR resistance observed in Japan.
authors.affiliation: *Division of Gastroenterology, National Hospital Organization, Tokyo Medical Center †Division of Gastroenterology and Hepatology, Department of Internal Medicine, Keio University School of Medicine ∥∥∥Department of Pharmacy, National Center for Global Health and Medicine, Tokyo ‡Division of Gastroenterology, National Hospital Organization, Kyoto Medical Center, Kyoto §Division of Gastroenterology, National Hospital Organization, Mie Central Medical Center, Mie ∥Division of Gastroenterology, National Kyushu Medical Center, Fukuoka ¶Division of Gastroenterology, National Hospital Organization, Saitama National Hospital, Wako #Division of Gastroenterology, National Hospital Organization, Beppu Medical Center, Beppu **Division of Gastroenterology, National Hospital Organization, Osaka Medical Center †††Division of Gastroenterology, National Hospital Organization, Osaka Minami Medical Center, Kawachinagano, Osaka ††Division of Gastroenterology, National Hospital Organization, Kanazawa Medical Center, Kanazawa, Ishikawa §§Division of Gastroenterology, National Hospital Organization, Fukuyama Medical Center ##Division of Gastroenterology, National Hospital Organization, Kure Medical Center, Hiroshima ∥∥Division of Gastroenterology, National Hospital Organization, Okayama Medical Center, Okayama ¶¶Division of Gastroenterology, National Hospital Organization, Asahikawa Medical Center, Asahikawa §§§Division of Gastroenterology, National Hospital Organization, Hokkaido Medical Center, Sapporo, Hokkaido ***Division of Gastroenterology, National Hospital Organization, Yonago Medical Center, Yonago, Tottori, Japan ‡‡Division of Gastroenterology, Kochi National Hospital, Kochi ‡‡‡Division of Gastroenterology, National Hospital Organization, Matsumoto Medical Center, Mesa, Matsumoto, Nagano.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Nishizawa
authors.forename: Takama
authors.initials: T
authors.lastname: Maekawa
authors.forename: Noriko
authors.initials: N
authors.lastname: Watanabe
authors.forename: Naohiko
authors.initials: N
authors.lastname: Harada
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Hosoda
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yoshinaga
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Yoshio
authors.forename: Hajime
authors.initials: H
authors.lastname: Ohta
authors.forename: Syuuji
authors.initials: S
authors.lastname: Inoue
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Toyokawa
authors.forename: Haruhiro
authors.initials: H
authors.lastname: Yamashita
authors.forename: Hiroki
authors.initials: H
authors.lastname: Saito
authors.forename: Toshio
authors.initials: T
authors.lastname: Kuwai
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Katayama
authors.forename: Eiji
authors.initials: E
authors.lastname: Masuda
authors.forename: Hideharu
authors.initials: H
authors.lastname: Miyabayashi
authors.forename: Toshio
authors.initials: T
authors.lastname: Kimura
authors.forename: Yuko
authors.initials: Y
authors.lastname: Nishizawa
authors.forename: Masahiko
authors.initials: M
authors.lastname: Takahashi
authors.forename: Hidekazu
authors.initials: H
authors.lastname: Suzuki
mesh_terms: D000368:Aged; D000658:Amoxicillin / Q000627:therapeutic use; D000890:Anti-Infective Agents / Q000627:therapeutic use*; D000897:Anti-Ulcer Agents / Q000627:therapeutic use; D001944:Breath Tests; D017291:Clarithromycin / Q000627:therapeutic use*; D024881:Drug Resistance, Bacterial / Q000187:drug effects; D004359:Drug Therapy, Combination; D005260:Female; D016481:Helicobacter Infections / Q000188:drug therapy*; D016480:Helicobacter pylori / Q000187:drug effects*; D006801:Humans; D007564:Japan; D008297:Male; D008795:Metronidazole / Q000627:therapeutic use*; D008875:Middle Aged; D011446:Prospective Studies; D064750:Rabeprazole / Q000627:therapeutic use; D014508:Urea
chemical_list: D000890:Anti-Infective Agents; D000897:Anti-Ulcer Agents; D008795:Metronidazole; D064750:Rabeprazole; D000658:Amoxicillin; D014508:Urea; D017291:Clarithromycin