Effect of oral omeprazole on basal and pentagastrin‐stimulated gastric secretion in young female horses

Abstract

SummaryOmeprazole (0.7 mg/kg bwt), as enteric‐coated pellets in capsules, was administered to 8 horses with chronic gastric cannulae to determine its effect on gastric juice acidity, acid output, pH, and volume. Omeprazole was given via nasogastric tube once daily for 5 days and gastric secretion tests were done on the 1st and 5th day of dosing. Gastric juice samples were collected every 15 mins from the cannula, starting 5 h after the administration of omeprazole. Basal secretion was determined in the first hour of collection followed by a 2‐h determination of pentagastrin (6 μg/kg/h)‐stimulated secretion. Lactose placebo studies were carried out in the same horses for comparison.Basal and stimulated gastric acid output were inhibited by 69% and 76%, respectively, by the 5th day of dosing, when compared with control values. Basal gastric juice pH increased from 3.2 in placebo‐treated horses to 4.6 by the 5th day of omeprazole treatment. Stimulated gastric juice pH was similarly increased from 1.7 to 4.6 by the 5th day of treatment.Omeprazole (0.7 mg/kg bwt) given orally once daily significantly inhibited basal and stimulated gastric acid secretion in horses by the 5th day of administration.