Pharmacokinetics of intravenous ciprofloxacin at three different doses.

The pharmacokinetics of ciprofloxacin were evaluated after single iv bolus injections of 50, 100 and 250 mg in eight young, healthy male volunteers. Concentrations were determined by high-performance liquid chromatography. The mean terminal half-life was 3.33, 3.73 and 3.45 h for 50, 100 and 250 mg doses, respectively. No significant differences between the three dose levels were noted for terminal half-life, total and renal clearances, distribution volume (Vd(ss] and percentage of dose recovered in urine over 24 h. The areas under the serum concentration curves were proportional to the given dose. We conclude that distribution and elimination of ciprofloxacin is not dose dependent.