Effects of cardiopulmonary bypass surgery on intravenous ciprofloxacin disposition

The pharmacokinetic parameters of intravenous ciprofloxacin were examined in five adult male patients on three separate occasions of open heart surgery: the 24 h before cardiopulmonary bypass (CPB) surgery, (PRE), during surgery (SURG), and 48 to 72 h after surgery (POST). Serial blood (n = 16), urine, and SURG tissue samples were collected after intravenous administration of a single 300-mg dose of ciprofloxacin during each study period. All samples were assayed for ciprofloxacin by a specific high-performance liquid chromatographic method. Serum ciprofloxacin concentrations remained constant or continued to decline during the course of CPB surgery. A significant (P < 0.05) decrease in total body clearance was observed during the SURG and POST phases (298 and 306 ml/min/1.73 m2, respectively) compared with that during the PRE phase (364 ml/min/1.73 m2). Renal clearances and elimination half-lives were similar during all three study phases. A nonsignificant decline occurred in the apparent volume of distribution, from mean values of 2.1 and 2.0 liters/kg during the PRE and POST phases, respectively, to 1.7 liters/kg during the SURG phase. The mediastinal fat tissue ciprofloxacin concentrations ranged from 0.45 to 2.89 micrograms/g. Overall, little significant difference was noted in the disposition of intravenous ciprofloxacin during CPB surgery compared with that before and after surgery.