Evaluation of a long-acting injectable formulation of omeprazole in healthy dogs

Background To evaluate the efficacy of a single intramuscular adminsitration of long-acting omeprazole (LA-OMEP) in increasing gastric pH in dogs. Hypothesis We hypothesized that LA-OMEP would meet in healthy dogs the clinical goals defined for human patients for treatment of gastroduodenal ulceration. Animals Nine healthy research dogs. Methods Prospective experimental study. Dogs were given a 4 mg/kg intramuscular injection of LA-OMEP. Intragastric pH was continuously recorded on treatment days 0 to 7. Daily mean pH and mean percentage time (MPT) intragastric pH was >= 3 or >= 4 were determined. Results The mean onset of action for the LA-OMEP was 98.11 min (SD 46.39). The mean number of days the dogs' pH met established goals for MPT pH >= 3 was 5.5 days (range, 3-7) and 5.25 days for MPT pH >= 4 (range, 3-7). Long-acting omeprazole met the human clinical goals pH >= 3 for 72 hours in 8/8 of the dogs and MPT pH >= 4 for 96 hours in 7/8 of dogs. Conclusions and Clinical Importance The LA-OMEP formulation produced gastric acid suppression in healthy dogs for an average of 5 days and up to 7 days, after a single intramuscular injection. No major adverse effects were observed.