Pharmacokinetics of ceftiofur sodium in equine pregnancy.
Eleven pregnant pony mares (D270-326) were administered ceftiofur sodium intramuscularly at 2.2 mg/kg (n = 6) or 4.4 mg/kg (n = 5), once daily. Plasma was obtained prior to ceftiofur administration and at 0.5, 1, 2, 4, 8, 12, and 24 hr after administration. Eight pony mares were re-enrolled in the study at least 3 days from expected foaling to ensure steady-state concentrations of drug at the time of foaling. Mares were administered ceftiofur sodium (4.4 mg/kg, IM) daily until foaling. Parturition was induced using oxytocin 1 hr after ceftiofur sodium administration. Allantoic and amniotic fluid, plasma, and colostrum samples were collected at time of foaling. Serial foal plasma samples were obtained. Placental tissues were collected. Desfuroylceftiofur acetamide (DCA) concentrations were measured in samples by high-performance liquid chromatography (HPLC). Mean (±SD) peak serum concentrations of DCA were 3.97 ± 0.50 μg/ml (low dose) and 7.45 ± 1.05 μg/ml (high dose). Terminal half-life was significantly (p = .014) shorter after administration of the low dose (2.91 ± 0.59 hr) than after administration of the high dose (4.10 ± 0.72 hr). The mean serum concentration of DCA from mares at time of foaling was 7.96 ± 1.39 μg/ml. The mean DCA concentration in colostrum was 1.39 ± 0.70 μg/ml. DCA concentrations in allantoic fluid, amniotic fluid, placental tissues, and foal plasma were below the limit of quantification (<0.1 μg/ml) and below the minimum inhibitory concentration of ceftiofur against relevant pathogens. These results infer incomplete passage of DCA across fetal membranes after administration of ceftiofur sodium to normal pony mares.
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
M L
http://orcid.org/0000-0002-4900-8850
ML
Macpherson
Department of Large Animal Medicine, College of Veterinary Medicine, University of Georgia, Athens, GA, USA.
S
S
Giguère
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
M A
MA
Pozor
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
E
E
Runcan
Department of Physiological Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
T W
TW
Vickroy
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
S A
SA
Benson
Gluck Equine Research Center, Department of Veterinary Science, University of Kentucky, Lexington, KY, USA.
M H T
MHT
Troedsson
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
J N
JN
Hatzel
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
J
J
Larson
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
E
E
Vanden Berg
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
A A
AA
Kelleman
Department of Large Animal Clinical Sciences, College of Veterinary Medicine, University of Florida, Gainesville, FL, USA.
L C
LC
Sanchez
Rood and Riddle Equine Hospital, Lexington, KY, USA.
M M
MM
LeBlanc
D000482:Allantois / Q000737:chemistry; D000653:Amniotic Fluid / Q000737:chemistry; D000818:Animals; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics*; D002511:Cephalosporins / Q000008:administration & dosage / Q000032:analysis / Q000097:blood / Q000493:pharmacokinetics*; D003126:Colostrum / Q000737:chemistry; D005260:Female; D005333:Fetus / Q000737:chemistry; D006207:Half-Life; D006736:Horses / Q000378:metabolism; D007273:Injections, Intramuscular / Q000662:veterinary; D007751:Labor, Induced / Q000662:veterinary; D010920:Placenta / Q000737:chemistry; D011247:Pregnancy / Q000378:metabolism
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; C053503:ceftiofur