In vitro activity and concentrations in serum, urine, prostatic secretion and adenoma tissue of ofloxacin in urological patients.

Studies in vitro showed that at concentrations of 1 and 4 mg/L ofloxacin inhibited 94 and 99% of the Gram-negative pathogens in isolates cultured from the urine of patients with complicated urinary tract infections (UTI). Against Gram-positive bacteria, 60 and 100% were inhibited at the corresponding concentrations. Comparisons of the MIC90 values of 8 quinolones showed the decreasing order of in vitro antibacterial activity to be ciprofloxacin, ofloxacin, norfloxacin, pefloxacin, enoxacin, pipemidic acid, nalidixic acid and cinoxacin. After an oral dose of ofloxacin 400mg, the mean peak serum concentration in 10 elderly patients was 5.5 mg/L and mean renal excretion during 24 hours was 41%. In 17 patients undergoing transurethral resection of the prostate, ofloxacin 400mg was given for perioperative prophylaxis. Two to 4.5 hours after administration, the median concentrations in prostatic secretion (5 patients) and prostatic adenoma tissue were 4.0 mg/L and 4.1 mg/kg, respectively. The corresponding serum concentrations of ofloxacin were 3.4 and 3.9 mg/L, respectively. In a group of 10 patients, 14.5 to 19.5 hours after oral administration of ofloxacin 400mg the median serum and prostatic adenoma tissue concentrations of ofloxacin were 1.9 mg/L and 1.2 mg/kg, respectively. The in vitro activity of ofloxacin concentrations attained in serum, urine, prostatic secretion and adenoma tissue show that it appears to be well suited for the treatment of complicated UTI.