title: Effect of dosing schemes of amoxicillin on eradication rates of Helicobacter pylori with amoxicillin-based triple therapy.
abstract: OBJECTIVE
  In standard regimens for Helicobacter pylori infection, amoxicillin is dosed twice daily, although the bactericidal effect of amoxicillin depends on the %time-above-MIC. We aimed to examine whether dosing schemes of amoxicillin influenced eradication rates of amoxicillin-based regimens.
  
  
  METHODS
  One hundred eighty-seven patients infected with clarithromycin-sensitive strains of H. pylori were treated with PPI, clarithromycin 200 mg bid and amoxicillin 750 mg bid, 500 mg tid or 500 mg qid for 1 week and 125 infected with clarithromycin-resistant strains were treated with PPI, metronidazole 250 mg bid and amoxicillin 750 mg bid, 500 mg tid or 500 mg qid for 1 week.
  
  
  RESULTS
  Eradication rates (ITT) of the triple PPI/amoxicillin/clarithromycin therapy with bid, tid and qid dosings of amoxicillin were 77.8% (49/63), 93.5% (58/62), and 91.9% (57/62), respectively. Those of the triple PPI/amoxicillin/metronidazole therapy were 80.5% (33/41), 90.5% (38/42), and 95.2% (40/42), respectively. Eradication rates in regimens with tid and qid dosing of amoxicillin were higher than those of regimens with the bid dosing of amoxicillin.
  
  
  CONCLUSIONS
  The dosing scheme of amoxicillin significantly influenced eradication rates of triple therapies. Although amoxicillin is empirically dosed twice daily, amoxicillin should be dosed at least three times daily in amoxicillin-based triple therapies.
authors.affiliation: Center for Clinical Research, Hamamatsu University School of Medicine, Hamamatsu, Japan.
authors.forename: Takahisa
authors.initials: T
authors.lastname: Furuta
authors.forename: Mitsushige
authors.initials: M
authors.lastname: Sugimoto
authors.forename: Mihoko
authors.initials: M
authors.lastname: Yamade
authors.forename: Takahiro
authors.initials: T
authors.lastname: Uotani
authors.forename: Shu
authors.initials: S
authors.lastname: Sahara
authors.forename: Hitomi
authors.initials: H
authors.lastname: Ichikawa
authors.forename: Takanori
authors.initials: T
authors.lastname: Yamada
authors.forename: Satoshi
authors.initials: S
authors.lastname: Osawa
authors.forename: Ken
authors.initials: K
authors.lastname: Sugimoto
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Watanabe
authors.forename: Kazuo
authors.initials: K
authors.lastname: Umemura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000658:Amoxicillin / Q000008:administration & dosage*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage*; D001944:Breath Tests; D017291:Clarithromycin / Q000008:administration & dosage; D004334:Drug Administration Schedule; D004359:Drug Therapy, Combination; D005260:Female; D005750:Gastric Juice / Q000382:microbiology; D016481:Helicobacter Infections / Q000175:diagnosis / Q000188:drug therapy* / Q000378:metabolism / Q000382:microbiology; D016480:Helicobacter pylori / Q000302:isolation & purification; D006801:Humans; D008297:Male; D008795:Metronidazole / Q000008:administration & dosage; D008875:Middle Aged; D054328:Proton Pump Inhibitors / Q000008:administration & dosage; D016896:Treatment Outcome; D014508:Urea / Q000378:metabolism; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D054328:Proton Pump Inhibitors; D008795:Metronidazole; D000658:Amoxicillin; D014508:Urea; D017291:Clarithromycin
keywords: H. pylori; amoxicillin; dosing scheme; eradication