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

Background and Purpose: To compare the concentrations of two fluoroquinolon es, ofloxacin (OFLX) and norfloxacin (NFLX), in the prostate gland of patie nts who underwent transurethral resection of the prostate (TUR-P) after ora l ingestion of both drugs for surgical prophylaxis. Methods: Ten patients with clinical symptoms of benign prostatic hyperplasi a undergoing TUR-P received 200 mg of both drugs per os simultaneously 2 ho urs before surgery. The concentrations of the drugs in the serum and prosta te at the time of surgery were measured by high performance liquid chromato graphy. Patients' clinical characteristics were evaluated, including findin gs from transrectal ultrasonography of the prostate, prostate specific anti gen concentration, renal function tests, and postoperative status. Results: Two hours after administration, the mean serum concentration of OF LX 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 (ra nge 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 concentrat ions of both drugs exceeded the minimum inhibitory concentration (MIC) for most gram-negative organisms, but NFLX maybe tillable to exceed the MIC90 o f 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 pene tration into the prostate (P/S ratio) (p < 0.001). The results of this stud y indicated that the concentrations of both of these drugs exceeded the MIC for most gram-negative organisms.