title: The pharmacokinetics of ketamine administered intravenously in calves and the modifying effect of premedication with xylazine hydrochloride.
abstract: Ketamine hydrochloride was administered intravenously to unpremedicated and xylazine-treated calves. The plasma concentrations of ketamine and norketamine were measured at several time intervals after drug administration and the data were fitted to a two-compartment open model. In unpremedicated female calves the distribution and elimination half-lives averaged 6.9 and 60.5 min, respectively. The volume of the central compartment was 1.21 l/kg and the peripheral compartment was 4.04 l/kg. Total body clearance of ketamine averaged 40.4 ml/min/kg. Premedication with xylazine, whilst not affecting the half-lives significantly, reduced volumes of distribution and the clearance rate of the drug by approximately 50%. The results for the male calves which were premedicated were intermediate between the two groups of female calves.
mesh_terms: D000375:Aging; D000818:Animals; D002417:Cattle; D005260:Female; D006207:Half-Life; D007275:Injections, Intravenous; D007649:Ketamine / Q000008:administration & dosage / Q000378:metabolism*; D007700:Kinetics; D008297:Male; D011229:Preanesthetic Medication / Q000662:veterinary*; D013843:Thiazines / Q000494:pharmacology*; D014991:Xylazine / Q000494:pharmacology*
chemical_list: D013843:Thiazines; D014991:Xylazine; D007649:Ketamine