title: Effect of Timing of Proton Pump Inhibitor Administration on Acid Suppression.
abstract: BACKGROUND
  Esomeprazole has been reported to show a strong acid suppression following preprandial as compared to postprandial administration, though no known study has compared the acid suppressing effects of other proton pump inhibitors between those administrations. The aim of this study was to compare intragastric pH levels following pre- and postprandial administrations of rabeprazole and esomeprazole.
  
  
  METHODS
  In 15 Helicobacter pylori-negative healthy volunteers, we measured intragastric pH after 7 days of pre- and postprandial administrations of rabeprazole (10 mg) or esomeprazole (20 mg) using a 5-way crossover design.
  
  
  RESULTS
  Preprandial administration of esomeprazole showed stronger acid suppression than postprandial administration. The values for percent time at pH >4.0 over a 24-hour period increased from 45.3% with postprandial administration of esomeprazole to 54.4% with preprandial administration, while the percent time at pH >4.0 during daytime was increased to a greater extent from 51.4 to 66.5% with preprandial administration (p = 0.05). On the other hand, the acid suppressing effect of rabeprazole was not influenced by the timing of administration.
  
  
  CONCLUSIONS
  The acid suppressing effect of esomeprazole is influenced by administration timing. In contrast, the acid suppressing effect of rabeprazole is not augmented by preprandial administration.
authors.affiliation: Second Department of Internal Medicine, Shimane University School of Medicine, Shimane, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Furuta
authors.forename: Kyoichi
authors.initials: K
authors.lastname: Adachi
authors.forename: Masahito
authors.initials: M
authors.lastname: Aimi
authors.forename: Shino
authors.initials: S
authors.lastname: Shimura
authors.forename: Hironobu
authors.initials: H
authors.lastname: Mikami
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Nishimura
authors.forename: Norihisa
authors.initials: N
authors.lastname: Ishimura
authors.forename: Shunji
authors.initials: S
authors.lastname: Ishihara
authors.forename: Kohji
authors.initials: K
authors.lastname: Naora
authors.forename: Yoshikazu
authors.initials: Y
authors.lastname: Kinoshita
mesh_terms: D000328:Adult; D018592:Cross-Over Studies; D064098:Esomeprazole / Q000008:administration & dosage* / Q000494:pharmacology; D005215:Fasting; D005260:Female; D005744:Gastric Acid; D005745:Gastric Acidity Determination; D064368:Healthy Volunteers; D006801:Humans; D006863:Hydrogen-Ion Concentration / Q000187:drug effects*; D008297:Male; D019518:Postprandial Period; D054328:Proton Pump Inhibitors / Q000008:administration & dosage* / Q000494:pharmacology; D064750:Rabeprazole / Q000008:administration & dosage* / Q000494:pharmacology; D013270:Stomach / Q000187:drug effects*; D055815:Young Adult
chemical_list: D054328:Proton Pump Inhibitors; D064750:Rabeprazole; D064098:Esomeprazole