title: Effects of intramuscular omeprazole on gastric acid secretion in horses over a twenty-four hour period.
abstract: The effect of intramuscular (i.m.) omeprazole (0.25 or 1.0 mg/kg bwt; LD and HD), respectively, on volume, total acid output (TAO) and pH of the gastric juice was studied during 24 h in 5 horses with a chronically implanted gastric cannula. Whether secretion in controls was basal or stimulated with pentagastrin (8 micrograms/kg bwt/h), volume (NS) and TAO (P < 0.01, NS) gradually decreased and pH increased (P < 0.05, NS). Omeprazole significantly reduced the average basal TAO by 49 +/- 6% (LD) and 88 +/- 3% (HD) and the stimulated TAO by 64 +/- 2% and 97 +/- 1%. Basal pH in controls was 2.1-4.2 and after omeprazole treatment, pH 2.8-4.1 (LD) and 2.4-6.6 (HD). After stimulation, the corresponding pH values were 2.6-3.3, 3.9-4.9 and 5.4-7.2. The biological availability of omeprazole was 70-80%. Due to the simplicity of the administration technique and the higher biological availability, intramuscular administration may offer a practical and less expensive way of treating gastric ulcers in horses.
authors.affiliation: Department of Animal Physiology, Faculty of Veterinary Medicine, Swedish University of Agricultural Sciences, Uppsala, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Sandin
authors.forename: F M
authors.initials: FM
authors.lastname: Andrews
authors.forename: J A
authors.initials: JA
authors.lastname: Nadeau
authors.forename: T J
authors.initials: TJ
authors.lastname: Doherty
authors.forename: G
authors.initials: G
authors.lastname: Nilsson
mesh_terms: D000818:Animals; D000897:Anti-Ulcer Agents / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D019540:Area Under Curve; D001682:Biological Availability; D002940:Circadian Rhythm; D005260:Female; D005744:Gastric Acid / Q000378:metabolism*; D005750:Gastric Juice / Q000187:drug effects* / Q000378:metabolism; D006736:Horses / Q000378:metabolism / Q000502:physiology*; D006863:Hydrogen-Ion Concentration; D007273:Injections, Intramuscular / Q000662:veterinary; D008297:Male; D009853:Omeprazole / Q000008:administration & dosage / Q000097:blood / Q000494:pharmacology*; D012016:Reference Values
chemical_list: D000897:Anti-Ulcer Agents; D009853:Omeprazole