Preliminary investigations into a novel, long‐acting, injectable, intramuscular formulation of omeprazole in the horse

Abstract

The results of the present study compare favourably with previous reports on the pharmacodynamics of omeprazole and the clinical outcomes of trials reporting response to oral omeprazole therapy.

A study investigating the treatment of equine squamous gastric disease with long‐acting injectable or oral omeprazole

“…Long‐acting injectable omeprazole has been demonstrated to suppress acid production more markedly, more consistently and for longer than observed in previous investigations using ORLO (Sykes, Kathawala, et al, ; Sykes, Underwood, McGowan, & Mills, ) so the difference between treatments seen in the current study was expected. In the current study, excluding 1 horse that was subjected to euthanasia as a result of lameness, all horses with ESGD healed after 4 weeks of LAIO treatment in line with the 100% healing rate reported in a previous study when horses with ESGD were treated with LAIO for 2 weeks (Sykes, Kathawala, et al, ). After two weeks of treatment in the current study, not all lesions had healed, but resolution in 86% of cases was comparable with the 100% (95% CI 89%–100%) reported by Sykes et al (2017) given the small case numbers in both studies.…”

“…Parenteral administration of omeprazole for the treatment of ESGD had been reported (Andrews et al, ; Jenkins et al, ; Sandin, Andrews, Nadeau, Doherty, & Nilsson, ) prior to the recent report of LAIO (Sykes, Kathawala, et al, ). The administration of soluble omeprazole preparations results in a significant increase in gastric pH; however, there is marked variability between individual horses and changes in pH are inconsistent (Andrews et al, ; Jenkins et al, ; Sandin et al, ).…”

“…The use of daily intravenous administration of omeprazole has been reported (Andrews et al, ) but the short half‐life and need for daily intravenous injections limits the practical application of this form of treatment in equine practice. Recently, the use of a long‐acting intramuscular omeprazole preparation (LAIO) that is administered weekly has been reported (Sykes, Kathawala, et al, ). This preparation was reported to have superior pharmacodynamics to ORLO, and the use of 2 doses of LAIO 7 days apart was associated with 100% healing in 22 Thoroughbred racehorses with ESGD (Sykes, Kathawala, et al, ).…”

“…Recently, the use of a long‐acting intramuscular omeprazole preparation (LAIO) that is administered weekly has been reported (Sykes, Kathawala, et al, ). This preparation was reported to have superior pharmacodynamics to ORLO, and the use of 2 doses of LAIO 7 days apart was associated with 100% healing in 22 Thoroughbred racehorses with ESGD (Sykes, Kathawala, et al, ). The following study evaluated LAIO in a different population of horses.…”

Highlights of recent clinically relevant papers

“…This two‐part study by Ben Sykes and colleagues in Australia investigated the pharmacodynamics of long‐acting injectable omeprazole (LA‐OMEP) and its efficacy in a pilot clinical trial .…”