Rosoxacin and cinoxacin distribution in prostate, vagina, and female urethra. An experimental study in dogs.

Rosoxacin and cinoxacin, two new compounds structurally related to nalidixic acid, were investigated in dogs. Our primary interest was in the beneficial effects of the two drugs when used in the treatment of urinary tract infections. The distribution of rosoxacin and cinoxacin was investigated in prostatic tissue, prostatic interstitial fluid, and prostatic secretion, and in vaginal and female urethral secretions. Concentrations of both antibiotics were also measured in plasma, various tissues, and spinal fluid. The amounts of rosoxacin and cinoxacin in all tested tissues, fluids, and secretions were in the range of the minimal inhibitory concentrations for most Gram negative organisms found in urinary tract infections. This suggested possible beneficial effects of these drugs when the infection involves the above tissues. Rosoxacin concentration ratios were higher than those of cinoxacin relative to plasma concentration in prostatic, vaginal, and urethral secretions, as well as in prostatic and other tissue. These ratio differences were explained by the different physiochemical properties of the two drugs.