Pharmacokinetics and pharmacodynamics of intravenous dexmedetomidine in the horse

作者：Rezende M L^*; Grimsrud K N; Stanley S D; Steffey E P; Mama K R

来源：Journal of Veterinary Pharmacology and Therapeutics, 2015, 38(1): 15-23.

DOI：10.1111/jvp.12138

The aim of the study was to describe the pharmacokinetics and selected pharmacodynamics of intravenous dexmedetomidine in horses. Eight adult horses received 5g/kg dexmedetomidine IV. Blood samples were collected before and for 10h after drug administration to determine dexmedetomidine plasma concentrations. Pharmacokinetic parameters were calculated using noncompartmental analysis. Data from one outlier were excluded from the statistical summary. Behavioral and physiological responses were recorded before and for 6h after dexmedetomidine administration. Dexmedetomidine concentrations decreased rapidly (elimination half-life of 8.03 +/- 0.84min). Time of last detection varied from 30 to 60min. Bradycardia was noted at 4 and 10min after drug administration (26 +/- 8 and 29 +/- 8beats/min respectively). Head height decreased by 70% at 4 and 10min and gradually returned to baseline. Ability to ambulate was decreased for 60min following drug administration, and mechanical nociceptive threshold was increased during 30min. Blood glucose peaked at 30min (134 +/- 24mg/dL) and borborygmi were decreased for the first hour after dexmedetomidine administration. Dexmedetomidine was quickly eliminated as indicated by the rapid decrease in plasma concentrations. Physiological, behavioral, and analgesic effects observed after dexmedetomidine administration were of short duration.

• 出版日期2015-2