PENETRATION OF GLYCOPEPTIDE ANTIBIOTICS IN NUCLEUS PULPOSUS

The penetration of the glycopeptide antibiotics vancomycin and teicopl anin into the nucleus pulposus of rabbits was studied. Blood samples w ere obtained at 0.5, 1, 4, 8, and 24 hours after intravenous administr ation of 30 mg/kg vancomycin or 16 mg/kg teicoplanin. Concentrations o f antibiotics were determined in tissue specimens and serum samples by fluorescence polarization immunoassays. Antimicrobial activity in the nucleus pulposus was determined with an agar diffusion method using a strain of Micrococcus luteus as the indicator organism. A peak concen tration of vancomycin in the nucleus pulposus was attained 8 hours aft er drug administration. Teicoplanin reached its maximum level and plat eaued 1 and 2 hours, respectively, after injection, and it remained un changed for the rest of the study. This microbiologic analysis showed that the nucleus pulposus contained an antimicrobial level of glycopep tide antibiotics after administration. Because rabbit nucleus pulposus is similar anatomically to that of humans, these results may have imp lications regarding the timing and choice of antibiotic administration .