title: Lansoprazole versus omeprazole: influence on meal-stimulated gastric acid secretion.
abstract: OBJECTIVE
  To investigate, by means of meal-stimulated acid secretion, the extent to which differences in plasma half-life, bioavailability and the recommended therapeutic dose can influence the antisecretory potency of lansoprazole and omeprazole.
  
  
  METHODS
  In this double-blind, placebo-controlled, crossover study, 10 healthy male volunteers received 15 mg or 30 mg lansoprazole, 20 mg or 40 mg omeprazole or placebo for 5 days, in a randomized order. Meal-stimulated acid secretion was determined by means of a homogenized test meal and intragastric titration.
  
  
  RESULTS
  On day 1, meal-stimulated acid secretion was decreased by 35% and 45% after administration of 15 mg or 30 mg lansoprazole, and by 16% and 42% after 20 mg or 40 mg omeprazole. After 3 and 5 days of dosing the decreases were 53% and 48% with 15 mg lansoprazole, 82% and 82% with 30 mg lansoprazole, 43% and 39% with 20 mg omeprazole, and 76% and 83% with 40 mg omeprazole. At all measuring points during the 5-day dosing periods, lansoprazole 15 mg and 30 mg proved superior to 20 mg omeprazole in inhibiting meal-stimulated gastric acid secretion, but the differences were only statistically significant for the lansoprazole 30 mg dose, 30 mg lansoprazole and 40 mg omeprazole proved equipotent. On day 1 only 30 mg lansoprazole was significantly better than placebo.
  
  
  CONCLUSIONS
  This study demonstrated the following order of antisecretory potency: 30 mg lansoprazole = 40 mg omeprazole > 15 mg lansoprazole approximately 20 mg omeprazole.
authors.affiliation: Clinical Research Hamburg, Scientific Institute, Germany.
authors.forename: H G
authors.initials: HG
authors.lastname: Dammann
authors.forename: W
authors.initials: W
authors.lastname: Fuchs
authors.forename: G
authors.initials: G
authors.lastname: Richter
authors.forename: F
authors.initials: F
authors.lastname: Burkhardt
authors.forename: N
authors.initials: N
authors.lastname: Wolf
authors.forename: T A
authors.initials: TA
authors.lastname: Walter
mesh_terms: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D000328:Adult; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000009:adverse effects / Q000494:pharmacology*; D005502:Food; D005744:Gastric Acid / Q000378:metabolism*; D006801:Humans; D064747:Lansoprazole; D008297:Male; D009853:Omeprazole / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology*; D054328:Proton Pump Inhibitors
chemical_list: D053799:2-Pyridinylmethylsulfinylbenzimidazoles; D004791:Enzyme Inhibitors; D054328:Proton Pump Inhibitors; D064747:Lansoprazole; D009853:Omeprazole