title: Pharmacokinetics of ceftiofur sodium and ceftiofur crystalline free acid in neonatal foals.
abstract: Ceftiofur, a third generation cephalosporin, demonstrates in vitro efficacy against microorganisms isolated from septicemic neonatal foals. This pharmacokinetic study evaluated the intravenous and subcutaneous administration of ceftiofur sodium (5 mg/kg body weight; n = 6 per group) and subcutaneous administration of ceftiofur crystalline free acid (6.6 mg/kg body weight; n = 6) in healthy foals. Plasma ceftiofur- and desfuroylceftiofur-related metabolite concentrations were measured using high performance liquid chromatography following drug administration. Mean (±SD) noncompartmental pharmacokinetic parameters for i.v. and s.c. ceftiofur sodium were: AUC(0→∝) (86.4 ± 8.5 and 91 ± 22 h·μg/mL for i.v. and s.c., respectively), terminal elimination half-life (5.82 ± 1.00 and 5.55 ± 0.81 h for i.v. and s.c., respectively), C(max(obs)) (13 ± 1.9 μg/mL s.c.), T(max(obs)) (0.75 ± 0.4 h for s.c.). Mean (± SD) noncompartmental pharmacokinetic parameters for s.c. ceftiofur crystalline free acid were: AUC(0→∝) (139.53 ± 22.63 h·μg/mL), terminal elimination half-life (39.7 ± 14.7), C(max(obs)) (2.52 ± 0.35 μg/mL) and t(max(obs)) (11.33 ± 1.63 h). No adverse effects attributed to drug administration were observed in any foal. Ceftiofur- and desfuroylceftiofur-related metabolites reached sufficient plasma concentrations to effectively treat common bacterial pathogens isolated from septicemic foals.
authors.affiliation: William R. Pritchard Veterinary Medical Teaching Hospital Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA.
authors.forename: T L
authors.initials: TL
authors.lastname: Hall
authors.forename: L A
authors.initials: LA
authors.lastname: Tell
authors.forename: S E
authors.initials: SE
authors.lastname: Wetzlich
authors.forename: J D
authors.initials: JD
authors.lastname: McCormick
authors.forename: L W
authors.initials: LW
authors.lastname: Fowler
authors.forename: N
authors.initials: N
authors.lastname: Pusterla
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002511:Cephalosporins / Q000008:administration & dosage / Q000097:blood / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid / Q000662:veterinary; D005260:Female; D006736:Horses / Q000378:metabolism*; D007275:Injections, Intravenous / Q000662:veterinary; D007279:Injections, Subcutaneous / Q000662:veterinary; D008297:Male
chemical_list: D000900:Anti-Bacterial Agents; D002511:Cephalosporins; C053503:ceftiofur