title: Comparative plasma pharmacokinetics of ceftiofur sodium and ceftiofur crystalline-free acid in neonatal calves.
abstract: The objective of this study was to compare the plasma pharmacokinetic profile of ceftiofur crystalline-free acid (CCFA) and ceftiofur sodium in neonatal calves between 4 and 6 days of age. In one group (n = 7), a single dose of CCFA was administered subcutaneously (SQ) at the base of the ear at a dose of 6.6 mg/kg of body weight. In a second group (n = 7), a single dose of ceftiofur sodium was administered SQ in the neck at a dose of 2.2 mg/kg of body weight. Concentrations of desfuroylceftiofur acetamide (DCA) in plasma were determined by HPLC. Median time to maximum DCA concentration was 12 h (range 12-48 h) for CCFA and 1 h (range 1-2 h) for ceftiofur sodium. Median maximum plasma DCA concentration was significantly higher for calves given ceftiofur sodium (5.62 μg/mL; range 4.10-6.91 μg/mL) than for calves given CCFA (3.23 μg/mL; range 2.15-4.13 μg/mL). AUC0-∞ and Vd/F were significantly greater for calves given CCFA than for calves given ceftiofur sodium. The median terminal half-life of DCA in plasma was significantly longer for calves given CCFA (60.6 h; range 43.5-83.4 h) than for calves given ceftiofur sodium (18.1 h; range 16.7-39.7 h). Cl/F was not significantly different between groups. The duration of time median plasma DCA concentrations remained above 2.0 μg/mL was significantly longer in calves that received CCFA (84.6 h; range 48-103 h) as compared to calves that received ceftiofur sodium (21.7 h; range 12.6-33.6 h). Based on the results of this study, CCFA administered SQ at a dose of 6.6 mg/kg in neonatal calves provided plasma concentrations above the therapeutic target of 2 μg/mL for at least 3 days following a single dose. It is important to note that the use of ceftiofur-containing products is restricted by the FDA and the use of CCFA in veal calves is strictly prohibited.
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Woodrow
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA.
authors.forename: M
authors.initials: M
authors.lastname: Caldwell
authors.affiliation: Department of Comparative Medicine, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA.
authors.forename: S
authors.initials: S
authors.lastname: Cox
authors.affiliation: Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Tennessee, Knoxville, TN, USA.
authors.forename: M
authors.initials: M
authors.lastname: Hines
authors.affiliation: Department of Population Health, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
authors.forename: B C
authors.initials: BC
authors.lastname: Credille
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D000900:Anti-Bacterial Agents / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D019540:Area Under Curve; D002417:Cattle / Q000097:blood*; D002511:Cephalosporins / Q000097:blood / Q000378:metabolism / Q000493:pharmacokinetics*; D006207:Half-Life
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; C063324:desfuroylceftiofur; C053503:ceftiofur