Pharmacokinetics of intravenous and intramuscular buprenorphine in the horse
Version of Record online: 11 MAR 2011
© 2011 Blackwell Publishing Ltd
Journal of Veterinary Pharmacology and Therapeutics
Volume 35, Issue 1, pages 52–58, February 2012
How to Cite
DAVIS, J. L., MESSENGER, K. M., LaFEVERS, D. H., BARLOW, B. M. and POSNER, L. P. (2012), Pharmacokinetics of intravenous and intramuscular buprenorphine in the horse. Journal of Veterinary Pharmacology and Therapeutics, 35: 52–58. doi: 10.1111/j.1365-2885.2011.01284.x
- Issue online: 6 JAN 2012
- Version of Record online: 11 MAR 2011
- (Paper received 21 September 2010; accepted for publication 21 January 2011)
Davis, J. L., Messenger, K. M., LaFevers, D. H., Barlow, B. M., Posner, L. P. Pharmacokinetics of intravenous and intramuscular buprenorphine in the horse. J. vet. Pharmacol. Therap. 35, 52–58.
The purpose of this study was to determine the pharmacokinetics of buprenorphine following intravenous (i.v.) and intramuscular (i.m.) administration in horses. Six horses received i.v. or i.m. buprenorphine (0.005 mg/kg) in a randomized, crossover design. Plasma samples were collected at predetermined times and horses were monitored for adverse reactions. Buprenorphine concentrations were measured using ultra-performance liquid chromatography with electrospray ionization mass spectrometry. Following i.v. administration, clearance was 7.97 ± 5.16 mL/kg/min, and half-life (T1/2) was 3.58 h (harmonic mean). Volume of distribution was 3.01 ± 1.69 L/kg. Following i.m. administration, maximum concentration (Cmax) was 1.74 ± 0.09 ng/mL, which was significantly lower than the highest measured concentration (4.34 ± 1.22 ng/mL) after i.v. administration (P < 0.001). Time to Cmax was 0.9 ± 0.69 h and T1/2 was 4.24 h. Bioavailability was variable (51–88%). Several horses showed signs of excitement. Gut sounds were decreased 10 ± 2.19 and 8.67 ± 1.63 h in the i.v. and i.m. group, respectively. Buprenorphine has a moderate T1/2 in the horse and was detected at concentrations expected to be therapeutic in other species after i.v. and i.m. administration of 0.005 mg/kg. Signs of excitement and gastrointestinal stasis may be noted.