Dose- and sex-independent disposition of ciprofloxacin.

Serum concentrations and urinary excretion of ciprofloxacin were studied in female and male volunteers following a single oral administration of 100 mg, 250 mg, 500 mg or 1000 mg. Serum and urine concentrations increased proportionally to the increasing dose administered but independently of sex. Twenty-five percent of the administered dose was excreted in the urine as unmetabolized ciprofloxacin within the first 24 hours after oral administration. Renal clearance averaged 5 ml/min X kg.