Abstract

The pharmacokinetics and effects of the opioid methadone on behaviour, arterial blood pressure, heart rate and haematocrit were studied in goats. Two goats received methadone (0.2 mg/kg) intravenously and the terminal half-life was 88 and 91 min, the volume of distribution 8.4 and 6.1 L/kg, and clearance 86 and 123 mL/min/kg. In a crossover study eight goats received methadone (0.6 mg/kg) or 0.15 M NaCl subcutaneously (SC). After SC administration bioavailability was complete and the terminal half-life was 215 +/- 84 min (mean +/- SD), T-max 31 +/- 15 min and C-max 45 +/- 11 ng/mL. Blood pressure and haematocrit increased while heart rate did not change. The goats did not ruminate and they climbed, scratched, gnawed and showed tail-flicking after SC methadone in contrast to NaCl administration. The use of methadone in goats may be restricted due to the inhibition of rumination and the rather short half-life. (c) 2013 Elsevier Ltd. All rights reserved.

Keywords

Heart rate; Haematocrit; PK/PD; Opioids; Ruminate

Published in

Research in Veterinary Science
2013, Volume: 95, number: 1, pages: 231-237
Publisher: ELSEVIER SCI LTD

SLU Authors

• Olsén, Lena

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Olsson, Kerstin

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Sandberg, Eva

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

• Ingvast Larsson, Carina

  • Department of Animal Biosciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Other Veterinary Science


Publication identifier

DOI: https://doi.org/10.1016/j.rvsc.2013.02.013

Permanent link to this page (URI)

https://res.slu.se/id/publ/53395