Plasma Concentration of Butorphanol in Northern Royal Albatross Undergoing Fracture Repair

Aims: The objective of this study was to determine the plasma concentration of butorphanol injected intravenously at 4mg/kg dose in Northern Royal Albatross and compare the pharmacokinetic parameters with that of broiler chickens. Methods: The plasma concentration of butorphanol was analysed by High Performance Liquid Chromatography. The pharmacokinetic parameters were calculated by non-compartmental approach using standard equations in spreadsheet. Results: The half-life, volume of distribution, clearance, mean residence time were 94.4 minutes, 860.5 ml/kg, 6.31 ml/kg/min, and 146.4 minutes, respectively. The levels remained above the minimum effective concentration for mammals for about 4 hours. Conclusion: Though we have data from only one albatross for butorphanol kinetics, it confirms the chicken data: butorphanol does not last as long in birds as in mammals. This shows that dose regimes for mammals are unsuitable for injured wild birds, but we can use chickens as a model for other wild bird species. The levels remained above the minimum effective concentration for mammals Clinical Relevance: Butorphanol can provide good post operative analgesia in wild birds. The broiler chickens may be used as a model of drug research for wild birds, but further work is required to establish this fact