title: Effects of rioprostil on gastric acid and pepsin secretion in man: a review of studies in healthy volunteers.
abstract: The antisecretory effect of rioprostil on acid and pepsin secretion stimulated by pentagastrin or a meal, or on the 24-h intragastric acidity is tested in four different studies in 33 healthy male volunteers using a double-blind, crossover design. The oral doses of rioprostil used are 50 micrograms, 100 micrograms, 150 micrograms, 200 micrograms, 300 micrograms and 600 micrograms; these are the results obtained: Rioprostil reduces basal H+ and pepsin output by more than 50%. Rioprostil, 300 micrograms and 600 micrograms, significantly reduces the 3-h pentagastrin-stimulated acid output by 43.5% and 58.9%, respectively, and the 3-h stimulated pepsin output by 41.1% and 66.5%, respectively (p = 0.01). Depending on the method used for intragastric titration the following percentages of inhibition of acid secretion are observed, 40%, 65%, and 75% with 150 micrograms, 300 micrograms, and 600 micrograms rioprostil respectively, with one method and 32%, 34%, and 79% with 25 micrograms, 50 micrograms, and 200 micrograms rioprostil respectively, with a somewhat modified technique. The differences observed in % inhibition between these two studies can be explained by the use of a different intragastric titration technique. Rioprostil, 300 micrograms and 600 micrograms, significantly inhibits night-time acid secretion (AUC x h, 2400 h-0800 h) by 52% and 73.5% when compared with placebo (p = 0.03). The calculated ED50 for acid inhibition is 86.5 micrograms of rioprostil.
authors.affiliation: Pharmaceutical Research Center, Bayer AG, Wuppertal, FRG.
authors.forename: P
authors.initials: P
authors.lastname: Demol
authors.forename: M V
authors.initials: MV
authors.lastname: Singer
authors.forename: H G
authors.initials: HG
authors.lastname: Dammann
authors.forename: C T
authors.initials: CT
authors.lastname: Richardson
authors.forename: T R
authors.initials: TR
authors.lastname: Weihrauch
mesh_terms: D000328:Adult; D000897:Anti-Ulcer Agents / Q000494:pharmacology*; D004311:Double-Blind Method; D005502:Food; D005744:Gastric Acid / Q000378:metabolism*; D006801:Humans; D008297:Male; D010418:Pentagastrin; D010434:Pepsin A / Q000378:metabolism*; D011458:Prostaglandins E / Q000494:pharmacology*; D011465:Prostaglandins, Synthetic / Q000494:pharmacology; D016032:Randomized Controlled Trials as Topic; D016630:Rioprostil
chemical_list: D000897:Anti-Ulcer Agents; D011458:Prostaglandins E; D011465:Prostaglandins, Synthetic; D016630:Rioprostil; D010434:Pepsin A; D010418:Pentagastrin