Antibiotic pharmacokinetics in the inflamed prostate.

We hypothesized that altered pharmacokinetics in the inflamed prostate gland might account for the treatment failure of clinically diagnosed chronic bacterial prostatitis. We employed a rat model of chronic bacterial prostatitis to investigate any pharmacokinetic differences that may exist between uninflamed and inflamed prostate glands. Four groups of animals were studied (treated and untreated control and prostatitis groups). Seven days of norfloxacin therapy cured 60% of the animals with well-established bacterial prostatitis compared with a spontaneous cure rate of 10% in the nontreated prostatitis animals. Norfloxacin levels did not change significantly between the infected and noninfected prostate glands. We conclude that failure of antibiotic therapy in chronic bacterial prostatitis is not due to significantly altered norfloxacin pharmacokinetics in the chronically inflamed prostate gland but rather to the difficulty of eradicating protected bacterial microcolonies within an infection-induced altered microenvironment deep within the prostate gland.