Serum and plasma concentrations of clindamycin following a single intramuscular injection of clindamycin phosphate in maintenance haemodialysis patients and normal subjects.

Serum levels of clindamycin bioactivity and total clindamycin were studied after single intramuscular injections of 300 mg of clindamycin phosphate in a group of 6 normal subjects and a group of 6 maintenance haemodialysis patients. The patients were studied during a non-dialysis period and then again during haemodialysis. Peak levels tended to be higher and elimination half-lives shorter in the patients than in the normal subjects. Possible reasons for these differences are discussed. There was no evidence that haemodialysis per se influenced the pharmacokinetics of clindamycin phosphate. The proportion of unhydrolysed clindamycin phosphate tended to be higher in the renal failure patients and the reason for this is not apparent. Little, if any, dosage modification is necessary in severe renal fialure although there is probably little point in exceeding a dose of 300 mg intramuscularly every 5 h even in severe infections in patients with severe renal failure. The higher peak levels in patients with advanced renal failure indicate the need for further studies with repeated doses.