title: Effect on intragastric pH of a PPI with a prolonged plasma half-life: comparison between tenatoprazole and esomeprazole on the duration of acid suppression in healthy male volunteers.
abstract: OBJECTIVE
  To compare the inhibitory effect of a novel proton pump inhibitor (PPI), tenatoprazole 40 mg once daily, with esomeprazole 40 mg once daily on intragastric acidity.
  
  
  METHODS
  A randomized, investigator-blind, two-way, crossover study was conducted in 30 healthy Helicobacter pylori negative male volunteers. Tenatoprazole 40 mg or esomeprazole 40 mg was administered once daily for 7 consecutive days with a 4-wk washout period between treatments. Ambulatory 24-h intragastric pH was recorded at baseline, after 7 days' treatment, and 3 and 5 days after treatment was stopped.
  
  
  RESULTS
  At presumed steady-state (day 7), median 24-h pH values were 5.02 and 4.79 for tenatoprazole and esomeprazole, respectively. There was a significant difference between tenatoprazole and esomeprazole during the nocturnal period when mean pH was 4.64 +/- 0.67 versus 3.61 +/- 0.90, respectively (p < 0.0001), as well as a significantly higher mean percentage of time with pH >4 on tenatoprazole (72.5 +/- 14.9 vs 62.2 +/- 13.6, p < 0.0001). The effect of tenatoprazole was still present 5 days after treatment withdrawal especially during the night-time. The mean area under the plasma concentration-time curve and elimination half-time was significantly higher in the tenatoprazole group as compared with the esomeprazole group.
  
  
  CONCLUSIONS
  Tenatoprazole 40 mg daily provides a prolonged duration of acid suppression and a shorter nocturnal acid breakthrough in healthy volunteers, even after stopping the drug. Thus, tenatoprazole may provide greater clinical efficacy for patients in whom a once daily PPI is ineffective. Further studies are indicated.
authors.affiliation: Division of Gastroenterology, McMaster University Medical Centre, Hamilton, Ontario, Canada.
authors.forename: Richard H
authors.initials: RH
authors.lastname: Hunt
authors.forename: David
authors.initials: D
authors.lastname: Armstrong
authors.forename: Cindy
authors.initials: C
authors.lastname: James
authors.forename: Sadat K
authors.initials: SK
authors.lastname: Chowdhury
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Yuan
authors.forename: Paola
authors.initials: P
authors.lastname: Fiorentini
authors.forename: Alain
authors.initials: A
authors.lastname: Taccoen
authors.forename: Patrick
authors.initials: P
authors.lastname: Cohen
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000293:Adolescent; D000328:Adult; D000897:Anti-Ulcer Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology*; D018592:Cross-Over Studies; D064098:Esomeprazole / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology*; D005745:Gastric Acidity Determination; D006207:Half-Life; D006801:Humans; D007093:Imidazoles / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology*; D008297:Male; D054328:Proton Pump Inhibitors; D011725:Pyridines / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology*; D013270:Stomach / Q000187:drug effects*
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents; D007093:Imidazoles; D054328:Proton Pump Inhibitors; D011725:Pyridines; D064098:Esomeprazole; C119998:Tenatoprazole