PENETRATION OF CEFOTAXIME INTO INTERVERTEBRAL DISCS REMOVED FROM PATIENTS UNDERGOING DISCECTOMY

Abstract

The intervertebral disc is an avascular tissue, and penetration of antibiotics occurs by passive diffusion. Cefotaxime penetration has not been well studied. The aim is to investigate the penetration of cefotaxime into the intervertebral disc removed from patients undergoing discectomy. Twenty-six patients undergoing discectomy were recruited for this study. They were given one gram of cefotaxime intravenously as a prophylactic antibiotic. Cefotaxime was extracted from nucleus pulposus and serum and analyzed using an HPLC method with cefuroxime axetil as internal standard. Cefotaxime penetrated into all the 26 samples of nucleus pulposus resulting in a mean concentration of 0.66±0.13 µg/gm. The mean serum concentration at time of disc removal was 13.61±3.54 µg/ml. The concentration in 16 samples were below the minimum inhibitory concentration against Staph. aureus with an average of 0.27±0.03 µg/g. There is a statistically significant correlation between time after intravenous cefotaxime administration and its concentration in the nucleus pulposus. The greater increase is in the third hour after administration. Factors like age, body weight, gender, number of associated diseases and surgical history did not seem to affect nucleus pulposus cefotaxime concentration. In conclusion, cefotaxime can penetrate into the nucleus pulposus but its concentration is relatively low. This concentration has a strong positive correlation with time after cefotaxime intravenous administration. Cefotaxime, therefore, needs to be given at least two hours before disc removal, with re-dosing immediately before operation to maintain high serum concentration.

Keywords

• surgery
• cefotaxime concentration
• intervertebral disc
• nucleus pulposus
• discectomy3