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sSec_2">Purpose
sp0015">The objective of this study was to assess the C3–C4 intervertebral disc (IVD), C3 vertebral body cancellous bone, and subcutaneous adipose tissue (SCT) pharmacokinetics of cefuroxime by use of microdialysis in a large animal model.
sSec_3">Study Design
sp0020">This was a single-dose, dense sampling large animal study of cefuroxime spine penetration.
sSec_4">Methods
sp0025">Ten female pigs were assigned to receive 1,500 mg of cefuroxime intravenously over 15 minutes. Measurements of cefuroxime were obtained from plasma, SCT, vertebral cancellous bone, and IVD for 8 hours thereafter. Microdialysis was applied for sampling in solid tissues.
sSec_5">Results
sp0030">For both IVD and vertebral cancellous bone, the area under the concentration curve from zero to the last measured value (AUC<sub>0–lastsub>) was significantly lower than that of free plasma. As estimated by the ratio of tissue AUC<sub>0–lastsub> to plasma AUC<sub>0–lastsub>, tissue penetration (95% confidence interval) of cefuroxime was significantly incomplete for the IVD 0.78 (0.57; 0.99), whereas for vertebral cancellous bone 0.78 (0.51; 1.04) and SCT 0.94 (0.73; 1.15) it was not. The penetration of cefuroxime from plasma to the IVD was delayed, and the maximal concentration and the elimination of cefuroxime were also reduced compared with both SCT and vertebral cancellous bone. Because of this delay in elimination of cefuroxime, the time with concentrations above the minimal inhibitory concentration (T<sub>>MICsub>) was significantly longer in the IVD compared with the remaining compartments up to MICs of 6 µg/mL.
sSec_6">Conclusions
sp0035">Microdialysis was successfully applied for serial assessment of the concentration of cefuroxime in the IVD and the vertebral cancellous bone. Penetration of cefuroxime from plasma to IVD was found to be incomplete and delayed, but because of a prolonged elimination, superior T<sub>>MICsub> was found in the IVD up to MICs of 6 µg/mL.
