Comparison of ofloxacin and norfloxacin concentration in prostatic tissues in patients undergoing transurethral resection of the prostate

Background and Purpose: To compare the concentrations of two fluoroquinolones, ofloxacin (OFLX) and norfloxacin (NFLX), in the prostate gland of patients who underwent transurethral resection of the prostate (TUR-P) after oral ingestion of both drugs for surgical prophylaxis. Methods: Ten patients with clinical symptoms of benign prostatic hyperplasia undergoing TUR-P received 200 mg of both drugs per os simultaneously 2 hours before surgery. The concentrations of the drugs in the serum and prostate at the time of surgery were measured by high performance liquid chromatography. Patients' clinical characteristics were evaluated, including findings from transrectal ultrasonography of the prostate, prostate specific antigen concentration, renal function tests, and postoperative status. Results: Two hours after administration, the mean serum concentration of OFLX wads 4.14 +/- 0.64 mg/L (range 0.27-6.37) and of NFLX was 1.10 +/- 0.22 mg/L (range 0.02-2.1). The concentration of ORLX in prostatic tissue was 4.10 +/- 0.79 mug/g (range 1.70-6.37) and of NFLX was 2.22 +/- 0.57 mug/g (range 0.63-4.35). The ratio of the prostatic tissue concentration (P) to the serum concentration (S) was 2.11 for OFLX and 5.71 for NFLX. The concentrations of both drugs exceeded the minimum inhibitory concentration (MIC) for most gram-negative organisms, but NFLX maybe tillable to exceed the MIC90 of Enterobacter cloacae in some individuals. Leukocytosis and spicing fever developed after TUR-P in two of the 10 patients. Conclusions: Concentrations of OFLX were higher in both serum and prostatic adenoma tissues than those of NFLX (p < 0.001), while NFLX had better penetration into the prostate (P/S ratio) (p < 0.001). The results of this study indicated that the concentrations of both of these drugs exceeded the MIC for most gram-negative organisms.