Target animal safety test of a dexamethasone-prednisolone combination in horses

The target animal safety of a dexamethasone-prednisolone combination was studied on 12 horses divided into two groups of six each. One group of horses received the therapeutic dose of the combination (25 mg/animal dexamethasone pivalate and 75 mg/animal prednisolone) and the second group was given the threefold dose of it. The preparation was administered intravenously for 2 consecutive days. For assessment of safety a wide range of clinical, haematological, biochemical and urine variables were tested as laid down in the guidelines of the FDA. All horses treated by the therapeutic or the threefold therapeutic doses of the preparation remained in good health throughout the entire study. No signs of clinical abnormalities occurred in either group. The physiological variables tested failed to reveal any significant alteration as a consequence of the medications. Of the haematological and biochemical parameters leucocyte, neutrophil, eosinophil and lymphocyte counts, aspartate aminotransferase activity, glucose, phosphor, total and conjugated bilirubin and creatinine concentrations were significantly affected in both groups. In some animals a transient glucosuria occurred. From the direction and magnitude of these changes it was concluded that they did not reflect any toxic actions of the preparation. Nevertheless, the combination is to be administered only with exact therapeutic indications and the uncontrolled misuse of it must be avoided.