Pharmacokinetics of nalbuphine hydrochloride after intravenous and intramuscular administration to Hispaniolan Amazon parrots Amazona ventralis

Abstract

Objective-To assess the pharmacokinetics of nalbuphine HCl after IV and IM administrationto 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 acomplete randomized crossover study design; there was a washout period of 21 days betweensubsequent administrations. Plasma samples were obtained from blood collected atpredetermined time points for measurement of nalbuphine concentration by use of liquidchromatography-tandem mass spectrometry. Pharmacokinetic parameters were estimatedby use of computer software.Results-Nalbuphine was rapidly eliminated with a terminal half-life of 0.33 hours andclearance of 69.95 mL/min/kg after IV administration and a half-life of 0.35 hours after IMadministration. Volume of distribution was 2.01 L/kg after IV administration. The fraction ofthe dose absorbed was high (1.03) after IM administration. No adverse effects were detectedin the parrots during the study.Conclusions and Clinical Relevance-In Hispaniolan Amazon parrots, nalbuphine appearedto have good bioavailability after IM administration and was rapidly cleared afterIV and IM administration. Safety and analgesic efficacy of various nalbuphine treatmentregimens in this species require further investigation to determine the potential for clinicalpalliation of signs of pain in psittacine species.