Cinoxacin in urinary tract infections. Theoretical and practical considerations.

In dogs we found that cinoxacin concentrations in prostatic tissue, secretion, and interstitial fluid always were lower than the simultaneous serum concentrations, during constant infusion experiments. The cinoxacin concentrations in urethral and vaginal secretions were similar to those found in prostatic interstitial fluid, approximately one third to one fourth of the simultaneous serum concentrations. The concentrations of cinoxacin in human prostatic tissue after single or multiple doses of 500 mg. were found to be in the range of minimum inhibitory concentrations for most microorganisms found in urinary tract infections. Cinoxacin was found to have a half-life of 2.7 hours in patients with normal renal function, but increased to 8.5 hours in patients with impaired renal function. We found little or no drug accumulation during a seven-day treatment of patients with impaired renal function.