Pharmacokinetics of a Single Oral Dose of Robenacoxib in Hispaniolan Parrots (Amazona ventralis).

Robenacoxib is a coxib class nonsteroidal anti-inflammatory drug, and its mechanism of action involves selectively inhibiting cyclooxygenase (COX)-2 to reduce inflammation via the reduction of prostaglandin synthesis in dogs, cats, and rats. It is currently labeled for use in dogs and cats to control postoperative pain and inflammation associated with orthopedic surgery, ovariohysterectomy, and castration for a maximum of 3 days. Robenacoxib has been used anecdotally in avian species at doses ranging from 2-10 mg/kg every 3-7 days to manage pain associated with inflammation in various scenarios, including treatment of proventricular dilatation disease, orthopedic pain, such as arthritis and pododermatitis, and post nail and beak trims. Robenacoxib concentrates in inflamed tissues, and its clinical effects persist longer than its short terminal half-life in blood. In this study, the pharmacokinetic parameters of a single oral dose of robenacoxib were evaluated in a group of 7 healthy, adult Hispaniolan Amazon parrots (Amazona ventralis). The results indicated that a single 4-mg/kg oral dose of robenacoxib was well tolerated without any adverse clinical effects. The mean peak plasma concentration was reached at 0.45 hours, with a peak concentration of 88.75 ng/mL. The t1/2 was 1.3 ± 0.37 hours. The mean total body clearance per fraction of dose absorbed was 24.9 L/kg/hr. Robenacoxib was not detected in any bird 6 hours postadministration. Further pharmacodynamic studies of this drug, including defining the potency of robenacoxib against avian COX-1 and COX-2 enzymes, would provide stronger support for dose determination and the effectiveness of robenacoxib in psittacine birds.