Synovial fluid and plasma concentrations of ceftiofur after regional intravenous perfusion in the horse.
OBJECTIVE
To determine radiocarpal (RC) joint synovial fluid and plasma ceftiofur concentrations after regional intravenous perfusion (RIP) and systemic intravenous (IV) administration.


METHODS
Experimental cross-over study.


METHODS
Five normal adult horses.


METHODS
One RC joint was randomly selected for RIP and the contralateral RC joint was sampled to determine intrasynovial ceftiofur concentrations after IV administration. Wash-out between IV and RIP was > or = 14 days. After surgical introduction of an intraarticular catheter, ceftiofur (2 g) was administered under general anesthesia either IV or by RIP after tourniquet application. Plasma and synovial fluid were collected over 24 hours. Samples were analyzed using high-performance liquid chromatography with ultraviolet detection and the results were statistically analyzed using a linear mixed effect model.


RESULTS
Mean synovial fluid ceftiofur concentrations were consistently higher after RIP than after IV administration and were > 1 mug/mL (minimal inhibitory concentration [MIC] for common pathogens) for >24 hours. Mean synovial fluid peak concentration of ceftiofur after RIP and IV administration was 392.7+/-103.29 microg/mL at 0.5 hours postinjection (HPI) and 2.72+/-0.31 mug/mL at 1 HPI, respectively. Large variations in synovial fluid and plasma ceftiofur concentrations were observed between horses regardless of administration technique. RIP did not cause adverse effects.


CONCLUSIONS
Under the present experimental conditions RIP with ceftiofur (2 g) induced significantly higher intraarticular antibiotic concentrations in the RC joint in comparison with IV administration. Moreover, after RIP, synovial fluid ceftiofur concentrations remain above the MIC for common pathogens (1 microg/mL) for > 24 hours. No adverse effects from the technique or the antibiotic were observed.


CONCLUSIONS
RIP with high doses of ceftiofur may be a beneficial adjunctive therapy when treating equine synovial infections which are caused by cephalosporin susceptible microorganisms.
Pille
Frederik
F
Department of Surgery and Anaesthesiology of Domestic Animals, Ghent University, Faculty of Veterinary Medicine, Merelbeke, Belgium. frederik.pille@UGent.be
De Baere
Siegrid
S
Ceelen
Liesbeth
L
Dewulf
Jeroen
J
Croubels
Siska
S
Gasthuys
Frank
F
De Backer
Patrick
P
Martens
Ann
A
D000818:Animals; D000900:Anti-Bacterial Agents / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D019540:Area Under Curve; D002358:Cartilage, Articular / Q000378:metabolism*; D002408:Catheters, Indwelling / Q000662:veterinary; D002511:Cephalosporins / Q000009:adverse effects / Q000097:blood / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid / Q000379:methods / Q000662:veterinary; D018592:Cross-Over Studies; D004305:Dose-Response Relationship, Drug; D004333:Drug Administration Routes / Q000662:veterinary*; D006736:Horses / Q000378:metabolism*; D007262:Infusions, Intravenous / Q000662:veterinary; D007275:Injections, Intravenous / Q000662:veterinary; D007958:Leukocyte Count / Q000662:veterinary; D008297:Male; D008826:Microbial Sensitivity Tests; D011897:Random Allocation; D013582:Synovial Fluid / Q000166:cytology / Q000378:metabolism*
D000900:Anti-Bacterial Agents; D002511:Cephalosporins; C053503:ceftiofur