BIOAVAILABILITY OF CLINDAMYCIN DURING PERITONEAL-DIALYSIS

Clindamycin phosphate becomes biologically active only with cleavage of the phosphate ester bond. A rat model was used to examine the amount of biologically active clindamycin attainable in the dialysate and in the blood during peritoneal dialysis. Intravenous administration of 10 mg/kg clindamycin phosphate alone without peritoneal dialysis produced peak blood levels of 15-20 μg/ml. With peritoneal dialysis, blood levels of less than 5 μg/ml were achieved. When clindamycin phosphate was added to the dialysis fluid at an initial concentration of 10 mg/ml, less than 5 μg/ml of the active antibiotic can be detected in the dialysis return fluids. Even in rats with induced peritonitis, less than 15 μg/ml could be found in the dialysis returns. With or without peritonitis, less than 5 μg/ml of active clindamycin was attained in blood from peritoneal installation alone. The conversion of the ester to the active compound appears to be the major problem. It is recommended that in those clinical situations in which the patient requires peritoneal dialysis, an alternate antimicrobial agent be used in place of clindamycin to avoid infections in the abdominal cavity or the blood while under therapy.