Pharmacokinetics of oral tramadol in red-tailed hawks (Buteo jamaicensis)

Marcy J. Souza, University of Tennessee - Knoxville
Tomas Martin-Jimenez, University of Tennessee - Knoxville
Michael P. Jones, University of Tennessee - Knoxville
Sherry K. Cox, University of Tennessee - Knoxville

Abstract

Little research has been performed examining pain control in avian species, and analgesia is becoming increasingly important in veterinary medicine. Tramadol is a relatively new drug that provides analgesia by opioid (mu), serotonin and norepinephrine pathways, with minimal adverse effects. In this study, three red-tailed hawks were dosed orally (11 mg/kg) with tramadol. Blood was collected at various time points between 0 and 360 min and analyzed with HPLC to determine concentrations of tramadol and M1 (O-desmethyltramadol), the predominate active metabolite. Although plasma concentrations of tramadol and M1 associated with analgesia in any avian species is unknown, based on the obtained data and known therapeutic concentrations in humans, future studies should evaluate the analgesia associated with an oral dosage regimens of 15 mg/kg for red-tailed hawks. Pharmacodynamic studies are needed to better determine plasma concentrations of tramadol and M1 that are associated with analgesia in birds.