A new method for assaying antimicrobials in the prostate.

In this study we collected prostatectomy specimens from 20 men receiving selected preoperative antimicrobials: oral carbenicillin, norfloxacin, or ciprofloxacin. The prostatectomy specimens were then individually separated into stroma and epithelium. The intraprostatic differential concentrations were determined using High Performance Liquid Chromatography. The ratio of stromal to epithelial concentrations of the antimicrobials were calculated for carbenicillin (0.95), norfloxacin (1.28), and ciprofloxacin (1.1). The quinolones tended to have higher stromal concentrations (although this was not statistically significant). Carbenicillin was found in levels three times its MIC90 for Escherichia coli while the quinolones were detected in concentrations which greatly exceeded their E. coli MIC90S.