title: The pharmacodynamics and pharmacokinetics of S-tenatoprazole-Na 30 mg, 60 mg and 90 mg vs. esomeprazole 40 mg in healthy male subjects.
abstract: BACKGROUND
  Racemic tenatoprazole 40 mg/day provides more prolonged acid suppression than esomeprazole 40 mg/day.
  
  
  OBJECTIVE
  To compare pharmacodynamic and pharmacokinetic profiles of tenatoprazole and esomeprazole.
  
  
  METHODS
  A single-centre, double-blind, double-dummy, randomized, 4-way, cross-over study was conducted in 32 healthy male subjects. S-tenatoprazole-Na 30, 60 or 90 mg, or esomeprazole 40 mg was administered once daily for 5 days with 10-day washout intervals. The 24-h intragastric pH was recorded at baseline and on day 5 of each period.
  
  
  RESULTS
  On day 5, median pH (5.34 +/- 0.45 and 5.19 +/- 0.52 vs. 4.76 +/- 0.82, respectively, P < 0.002) and percentage time with pH > 4 (80 +/- 11 and 77 +/- 12, vs. 63 +/- 11 respectively, P < 0.0001) for 24-h were higher with S-tenatoprazole-Na 90 mg and 60 mg than esomeprazole. In nocturnal periods, S-tenatoprazole-Na 90 mg, 60 mg and 30 mg were superior to esomeprazole with regard to median pH (5.14 +/- 0.64, 4.94 +/- 0.65, 4.65 +/- 0.86 and 3.69 +/- 1.18 respectively, P < 0.0001) and percentage time with pH > 4 (77 +/- 12, 73 +/- 17, 64 +/- 17 and 46 +/- 17 respectively, P < 0.0001). Proportion of subjects with nocturnal acid breakthrough with S-tenatoprazole-Na 90 mg, 60 mg and 30 mg was significantly less than with esomeprazole (54.8, 43.3, 56.7 and 90.3 respectively, P < 0.04). The proportion of subjects with >16 hrs with pH >4 was significantly higher with S-tenatoprazole-Na 90 mg and 60 mg than with esomeprazole (87.1%, 83.3% and 41.9% respectively, P < 0.02).
  
  
  CONCLUSIONS
  S-tenatoprazole-Na produced significantly greater and more prolonged dose-dependent 24-h and nocturnal acid suppression than esomeprazole. S-tenatoprazole-Na may provide greater clinical efficacy compared with current PPIs for patients with ineffective once-daily therapy.
authors.affiliation: Farncombe Family Digestive Disease Research Institute, Division of Gastroenterology, McMaster University & Hamilton Health Sciences, Hamilton, ON, Canada. huntr@mcmaster.ca
authors.forename: R H
authors.initials: RH
authors.lastname: Hunt
authors.forename: D
authors.initials: D
authors.lastname: Armstrong
authors.forename: M
authors.initials: M
authors.lastname: Yaghoobi
authors.forename: C
authors.initials: C
authors.lastname: James
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000328:Adult; D000897:Anti-Ulcer Agents / Q000008:administration & dosage*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D064098:Esomeprazole / Q000008:administration & dosage* / Q000031:analogs & derivatives* / Q000493:pharmacokinetics / Q000494:pharmacology; D005744:Gastric Acid / Q000378:metabolism*; D006801:Humans; D007093:Imidazoles / Q000008:administration & dosage* / Q000493:pharmacokinetics / Q000494:pharmacology; D008297:Male; D054328:Proton Pump Inhibitors / Q000008:administration & dosage
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000897:Anti-Ulcer Agents; D007093:Imidazoles; D054328:Proton Pump Inhibitors; D064098:Esomeprazole; C119998:Tenatoprazole