Minocycline hydrochloride as a sclerosant for the treatment of simple renal cysts was evaluated. Cyst puncture was performed, and minocycline hydrochloride solution for intravenous administration was injected after aspiration. Of 154 cysts evaluated by ultrasound after 3 months or more, 69 were no longer demonstrable, 49 showed 50% or greater reduction in the maximum cyst diameter, and only 8 were unchanged or slightly increased in size. In contrast, only 1 of 20 cysts aspirated without minocycline hydrochloride injection (controls) showed 50% or greater reduction after 3 months. There was a significant difference in the reduction rates between the minocycline-treated group and control group (p < 0.01). These results suggest that minocycline hydrochloride is an effective sclerosant to treat simple renal cysts.

The pharmacokinetics of cefotaxime, a new semi-synthetic cephalosporin for injection, was studied in 30 subjects with various degrees of renal function after a single 1-gram intramuscular injection. Serum and urinary concentrations of cefotaxime and desacetyl cefotaxime were determined by high pressure liquid chromatography. The pharmacokinetic parameters of cefotaxime were obtained using a one-compartment open model. The mean serum half-life of the parent compound (cefotaxime), 0.87 h in normal subjects, was prolonged to 2.35 h in hemodialysis patients. There was a significant lineal correlation between the elimination rate constant of cefotaxime and creatinine clearance. The mean cumulative urinary recovery of the administered dose in the 24-hour urine was 51.7% as cefotaxime and 25 6% as desacetyl cefotaxime in normal subjects.

Biochemical analysis of renal cyst fluid was performed in 53 patients with simple renal cysts including 2 infected cases. The composition of noninfected cyst fluid tended to parallel that of serum. Additionally, the penetration of amikacin into cyst fluid was studied in 2 infected and in 11 noninfected patients following a single 200-mg intramuscular injection of amikacin. Drug levels in the fluid were below detection limit in the noninfected and approximately half or less of the serum values in the infected patients. These data may explain one of the reasons why infection of simple renal cysts is highly resistant to antimicrobial chemotherapy. The value of treatment by percutaneous aspiration and drainage of infected cysts is emphasized.

The elimination kinetics of cefotetan (YM09330), a new parenteral semisynthetic cephamycin derivative, were studied in eight healthy volunteers and 41 patients with renal insufficiency after the administration of a single 500-mg dose intravenously. Concentrations of cefotetan in serum and urine were determined by both bioassay and high-pressure liquid chromatography. The pharmacokinetic parameters for cefotetan were calculated on the basis of a two-compartment open model. Serum concentrations of cefotetan immediately after administration were approximately 180 ,ug/ml in all subjects regardless offunction; however, serum concentrations during the P-phase increased directly with the degree of renal impairment. The mean serum half-life during the p-phase was 3.0 h in normal subjects as compared with 13.1 h in hemodialysis patients. There was a linear correlation (P < 0.0001) between the elimination rate constant of cefotetan and creatinine clearance. The mean cumulative urinary recovery of cefotetan in the 24-h urine was 83.3% of the administered dose in normal subjects and decreased with reduced renal function.

The pharmacokinetics of a single 500-mg intramuscular dose of ceftizoxime were studied in 11 healthy adult volunteers and in 22 patients with various degrees of renal dysfunction. The mean serum half-life of ceftizoxime was 1.44 h in normal subjects and 30.2 h in hemodialysis patients. A significant correlation (P less than 0.001) between the elimination rate constant of ceftizoxime and creatinine clearance was demonstrated. The mean urinary recovery in normal subjects was 75.6% within 6 h of dosage; recovery decreased progressively with reduced renal function.