title: Pharmacokinetics and pharmacodynamics of carfentanil and naltrexone in female common eland (Taurotragus oryx).
abstract: The pharmacokinetic parameters of carfentanil and naltrexone were determined in the common eland (Taurotragus oryx). Six adult females were immobilized with xylazine (0.23 +/- 0.03 mg/kg i.m.) and carfentanil (0.0169 +/- 0.0005 mg/kg i.m.) for a 45-min period, during which time routine health care procedures were performed. Heart and respiration rates and body temperatures were monitored throughout the immobilization period. A single intramuscular injection of naltrexone (1.66 +/- 0.08 mg/kg i.m.) was sufficient for reversal. The eland were intermittently restrained in a hydraulic squeeze chute for serial blood sample collection via jugular venipuncture during immobilization and up to 48 hr post-immobilization. The quantification of carfentanil and naltrexone in the plasma was performed by liquid chromatography and mass spectroscopy methods. Carfentanil was rapidly absorbed following administration, with the peak plasma concentration (C(max)) at 13.8 min. Naltrexone was readily absorbed and reached C(max) at 23.4 +/- 16.8 min after administration. All animals stood 2.7 +/- 2.2 min after naltrexone administration. Carfentanil has a half-life of 7.7 hr, whereas naltrexone has a much shorter half-life of 3.7 hr. Although respiratory rates appeared to fluctuate widely among animals, heart rates and body temperature remained stable throughout the immobilization. Renarcotization was not noted as a major complication.
authors.affiliation: Audubon Nature Institute Center for Research of Endangered Species, 14001 River Road, New Orleans, Louisiana 70131, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Cole
authors.forename: Adrian
authors.initials: A
authors.lastname: Mutlow
authors.forename: Ramiro
authors.initials: R
authors.lastname: Isaza
authors.forename: James W
authors.initials: JW
authors.lastname: Carpenter
authors.forename: David E
authors.initials: DE
authors.lastname: Koch
authors.forename: Robert P
authors.initials: RP
authors.lastname: Hunter
authors.forename: Betsy L
authors.initials: BL
authors.lastname: Dresser
mesh_terms: D000701:Analgesics, Opioid / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000818:Animals; D000866:Antelopes / Q000097:blood / Q000378:metabolism / Q000502:physiology*; D019540:Area Under Curve; D001831:Body Temperature / Q000187:drug effects; D005260:Female; D005283:Fentanyl / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000493:pharmacokinetics; D008401:Gas Chromatography-Mass Spectrometry / Q000662:veterinary; D006207:Half-Life; D006339:Heart Rate / Q000187:drug effects; D007103:Immobilization / Q000379:methods / Q000662:veterinary*; D007273:Injections, Intramuscular / Q000662:veterinary; D008657:Metabolic Clearance Rate; D009271:Naltrexone / Q000008:administration & dosage / Q000493:pharmacokinetics*; D009292:Narcotic Antagonists / Q000008:administration & dosage / Q000493:pharmacokinetics*; D011897:Random Allocation; D012119:Respiration / Q000187:drug effects
chemical_list: D000701:Analgesics, Opioid; D009292:Narcotic Antagonists; D009271:Naltrexone; C017114:carfentanil; D005283:Fentanyl