Objective: To assess the pharmacokinetics of nalbuphine HCl after IV and IM administration to Hispaniolan Amazon parrots (Amazona ventralis).
Animals: 8 healthy adult Hispaniolan Amazon parrots of unknown sex.
Procedures: Nalbuphine HCl (12.5 mg/kg) was administered IV and IM to all birds in a complete randomized crossover study design; there was a washout period of 21 days between subsequent administrations. Plasma samples were obtained from blood collected at predetermined time points for measurement of nalbuphine concentration by use of liquid chromatography-tandem mass spectrometry. Pharmacokinetic parameters were estimated by use of computer software.
Results: Nalbuphine was rapidly eliminated with a terminal half-life of 0.33 hours and clearance of 69.95 mL/min/kg after IV administration and a half-life of 0.35 hours after IM administration. Volume of distribution was 2.01 L/kg after IV administration. The fraction of the dose absorbed was high (1.03) after IM administration. No adverse effects were detected in the parrots during the study.
Conclusions and clinical relevance: In Hispaniolan Amazon parrots, nalbuphine appeared to have good bioavailability after IM administration and was rapidly cleared after IV and IM administration. Safety and analgesic efficacy of various nalbuphine treatment regimens in this species require further investigation to determine the potential for clinical palliation of signs of pain in psittacine species.