title: Comparison of the antisecretory effects of omeprazole when administered intravenously, as acid-stable granules and as an oral paste in horses.
abstract: The antisecretory activity of omeprazole on gastric acid when administered i.v., intragastrically or per os, was evaluated in 2 female and 3 castrated male horses. Each horse had been prepared with a chronic indwelling gastric cannula. A single i.v. administration of omeprazole (1.5 mg/kg bwt) was effective in abolishing basal and pentagastrin (PG)-stimulated acid secretion. Once daily, nasogastric administration of omeprazole in acid-stable granules for 5 days inhibited acid secretion in a dose-dependent manner: 57% (1.5 mg/kg bwt) and 98% (5.0 mg/kg bwt) reduction of PG-stimulated acid secretion. The degree of inhibition was maintained over a 19 day treatment period with once daily dosing. A prototype oral paste formulation containing either acid-stable omeprazole granules or uncoated omeprazole powder was equipotent when compared to a similar dosage of acid-stable omeprazole granules administered by nasogastric tube. A dose-dependent inhibition was seen with the oral paste formulation containing omeprazole powder: 55% (1.5 mg/kg bwt) and 77% (3.0 mg/kg bwt) reduction of PG-stimulated acid secretion after 5 days. Therefore, a paste formulation of omeprazole powder may offer an effective, easily administered, once daily acid inhibitory treatment for gastric ulcer disease in horses.
authors.affiliation: Department of Animal Health, Merck Research Laboratories, Rahway, New Jersey 07065, USA.
authors.forename: M L
authors.initials: ML
authors.lastname: Haven
authors.forename: K
authors.initials: K
authors.lastname: Dave
authors.forename: J A
authors.initials: JA
authors.lastname: Burrow
authors.forename: A M
authors.initials: AM
authors.lastname: Merritt
authors.forename: D
authors.initials: D
authors.lastname: Harris
authors.forename: D
authors.initials: D
authors.lastname: Zhang
authors.forename: G J
authors.initials: GJ
authors.lastname: Hickey
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000897:Anti-Ulcer Agents / Q000008:administration & dosage* / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000008:administration & dosage* / Q000494:pharmacology; D005260:Female; D005750:Gastric Juice / Q000187:drug effects*; D006736:Horses / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007275:Injections, Intravenous / Q000662:veterinary; D007441:Intubation, Gastrointestinal / Q000662:veterinary; D008297:Male; D009824:Ointments; D009853:Omeprazole / Q000008:administration & dosage* / Q000494:pharmacology; D013535:Suspensions
chemical_list: D000897:Anti-Ulcer Agents; D004791:Enzyme Inhibitors; D009824:Ointments; D013535:Suspensions; D009853:Omeprazole