Effect of hemodialysis on total body clearance of chloramphenicol.

The effect of hemodialysis on the total body clearance (ClTB) of chloramphenicol was studied in two patients with renal failure and hepatic dysfunction. Chloramphenicol sodium succinate was administered intravenously eight hours before dialysis in doses of 20 and 26.1 mg/kg/day to Patients 1 and 2, respectively. Serum samples were taken at 48 hours after initiation of the drug, 2.5 hours after the last dose and 5 minutes into dialysis for Patient 1, and before dosing and at 0.5, 1, 2, 4, 6, 8 and 11 hours after dosing for Patient 2. Serum levels of chloramphenicol were measured by high-performance liquid chromatography. Chloramphenicol ClTB values on dialysis (162.2 and 118 ml/min for Patients 1 and 2, respectively) were 58% and 72% higher than off-dialysis ClTB values (102.9 and 69 ml/min) for Patients 1 and 2, respectively. Dialysis extraction ratios for chloramphenicol were 0.52 and 0.31 for Patients 1 and 2, respectively. Although the increased clearance of chloramphenicol that occurred during dialysis may be important only in patients with hepatic dysfunction, it is recommended that the normal maintenance dose of the drug be administered after dialysis to avoid the possibility of increased clearance.