Antagonistic effects of intravenous or epidural atipamezole on xylazine-induced dorsolumbar epidural analgesia in cattle

Vet J. 2003 Sep;166(2):194-7. doi: 10.1016/s1090-0233(03)00026-1.

Abstract

This study was performed to clarify the antagonistic actions of intravenous or epidural atipamezole on the sedative and analgesic effects of xylazine administered between the epidural fat and dura mater through the first interlumbar space in cattle. Cattle received 5 mL of a solution containing 0.05 mg x kg(-1) xylazine in 0.9% saline. Thirty minutes later, 5 mL of 0.9% saline was administered through the same needle (treatment 1) (XSE). In treatments 2 (XAE) and 3 (XAV), 5 mL of a solution containing 0.025 mg x kg(-1) atipamezole in 0.9% saline was administered epidurally or intravenously, respectively. Sedation and analgesia were similar in all three treatment groups and could be reversed by atipamezole given by either route. In the XAV treatment, the flank area relapsed into analgesia 25+/-5.8 min following reversal of the analgesic effect, and was maintained for 112.5+/-63.8 min. The present study confirmed that the sedative and analgesic effects of xylazine are completely reversed by atipamezole and can be influenced by the epidural fat in cattle. Furthermore, it seems probable that analgesia following epidural administration of xylazine is mediated by alpha(2)-adrenergic receptors, not by a local anaesthetic effect.

Publication types

  • Clinical Trial

MeSH terms

  • Adipose Tissue / chemistry
  • Adrenergic alpha-Antagonists / administration & dosage
  • Adrenergic alpha-Antagonists / pharmacokinetics
  • Adrenergic alpha-Antagonists / pharmacology*
  • Analgesia, Epidural / methods
  • Analgesia, Epidural / veterinary*
  • Animals
  • Cattle
  • Drug Interactions
  • Female
  • Imidazoles / administration & dosage
  • Imidazoles / pharmacokinetics
  • Imidazoles / pharmacology*
  • Infusions, Intravenous
  • Injections, Epidural
  • Male
  • Tissue Distribution
  • Xylazine / administration & dosage
  • Xylazine / pharmacokinetics
  • Xylazine / pharmacology*

Substances

  • Adrenergic alpha-Antagonists
  • Imidazoles
  • atipamezole
  • Xylazine