Comparative plasma pharmacokinetics of ceftiofur sodium and ceftiofur crystalline-free acid in neonatal calves

摘要

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 6days 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 6.6mg/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 2.2mg/kg of body weight. Concentrations of desfuroylceftiofur acetamide (DCA) in plasma were determined by HPLC. Median time to maximum DCA concentration was 12h (range 12-48h) for CCFA and 1h (range 1-2h) for ceftiofur sodium. Median maximum plasma DCA concentration was significantly higher for calves given ceftiofur sodium (5.62g/mL; range 4.10-6.91g/mL) than for calves given CCFA (3.23g/mL; range 2.15-4.13g/mL). AUC(0-) 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 (60.6h; range 43.5-83.4h) than for calves given ceftiofur sodium (18.1h; range 16.7-39.7h). Cl/F was not significantly different between groups. The duration of time median plasma DCA concentrations remained above 2.0g/mL was significantly longer in calves that received CCFA (84.6h; range 48-103h) as compared to calves that received ceftiofur sodium (21.7h; range 12.6-33.6h). Based on the results of this study, CCFA administered SQ at a dose of 6.6mg/kg in neonatal calves provided plasma concentrations above the therapeutic target of 2g/mL for at least 3days 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.