ATCvet code: QH02AB02
Pharmacodynamic properties
Dexamethasone is a highly potent corticosteroid. It has minimal mineralocorticosteroid activity and potent glucocorticosteroid activity. Dexamethasone has gluconeogenic, anti-inflammatory, anti-allergenic activity and it induces parturition. This veterinary medicinal product is a dexamethasone preparation with a rapid onset of activity and a relatively long duration of action. It contains the disodium phosphate ester and phenylpropionate ester of dexamethasone.
Pharmacokinetic particulars
After intramuscular administration, the two dexamethasone esters are resorbed from the injection site followed by immediate hydrolysation into the parent compound, dexamethasone. Dexamethasone sodium phosphate is resorbed rapidly from the injection site, thus ensuring a rapid onset of activity. Dexamethasone phenylpropionate is resorbed more slowly from the injection site, thus ensuring a prolonged duration of activity.
The time to reach maximum plasma levels of dexamethasone after intramuscular injection in cattle, horses, and dogs is within 60 minutes after injection. Elimination half-lives after intramuscular administration are between 30 and 96 hours depending on the species. This relatively long half-life is caused by the relatively slow resorption of dexamethasone phenylpropionate from the injection site and is a combination of absorption and elimination half-life. Bioavailability after intramuscular administration is approximately 100%.