Comparison of the effect of Omoguard and Gastroshield ongastric pH in fasted horses, and effects of differing doses ofthe generic omeprazole paste Gastrozol

摘要

The efficacy of Omoguard (omeprazole370mg/g) paste was compared withthat of Gastroshield paste (omeprazole370mg/g). To study the efficacy ofomeprazole in inhibiting gastric acidity,a pilot study was conducted to developa model for producing gastric acidity inhorses. It was established that gastricpH drops to 2 by withholding feed andwater for 19 - 21 hours. This model wasused in a formal bioequivalence study tocompare the efficacy of Omoguard andGastroshield in inhibiting gastric acidityin 10 horses. The two pastes, Omoguardand Gastroshield were administeredin a randomised cross-over design.Five horses were administered eachproduct for 5 days, samples of gastricfluid were then collected and analysedfor pH. Following a 10 day wash outthe horses were treated with the sameprotocol for the other product. The pHresults for gastric fluid samples followingboth treatments were within the range4.5 – 5.9, statistical analysis of the dataconfirmed that the two products wereequally effective in suppressing gastricacid production. An additional smallstudy in three horses was performedto measure the effect of Gastrozol(omeprazole 50mg/mL) on gastric pHin horses. Gastrozol is approved foradministration at a dose rate of 1 mg/kg. In this study Gastrozol at 1 mg/kgdid not result in an equivalent increasein gastric pH to Omoguard at 4 mg/kg. When Gastrozol was administeredat 4 mg/kg, it was equally effective atincreasing gastric pH.