Adequacy of a vancomycin dosing regimen in patients receiving high-flux hemodialysis.
BACKGROUND
Some investigators have recommended the convenient practice of administering vancomycin doses during the last hour of the hemodialysis treatment. Accepting that a greater amount of vancomycin is lost to dialysis with this recent approach, the objective of this study is to determine the pharmacokinetics of vancomycin and assess the adequacy of this dosing regimen in maintaining therapeutic predialysis concentrations.


METHODS
A sampling of 22 consecutive patients administered intradialytic vancomycin, 1 g, intravenously (IV) and maintenance doses of 500 mg during the last hour of high-flux dialysis sessions was studied. A population-modeling program and Bayesian pharmacokinetic analysis were used to identify all global and unique pharmacokinetic parameters of interest based on measured vancomycin predialysis concentrations.


RESULTS
For the 22 patients studied, this regimen achieved the targeted predialysis concentration range of 5 to 20 microg/mL for 96% of levels, whereas more narrowly within 5 to 15 microg/mL for 86% of levels. Average amount of vancomycin removed during a standardized 3- to 4-hour dialytic session ranged from 30% +/- 7% to 38% +/- 8%. Average elimination half-life of vancomycin on hemodialysis treatment was 5.4 hours (interquartile range, 5.0 to 5.9 hours). Patients showed an average predialysis plasma concentration of 11 +/- 3 microg/mL for the first 7 days of therapy.


CONCLUSIONS
Our results indicate that intradialytic dosing with vancomycin using a 1-g IV load and 500 mg IV with subsequent high-flux dialysis sessions conveniently maintains adequate predialysis plasma concentrations. The lack of drug accumulation with this regimen provides convincing support for a limited blood sampling approach to plasma concentration determinations.
Ariano
Robert E
RE
Department of Pharmacy, St Boniface General Hospital, Canada. rariano@sbgh.mb.ca
Fine
Adrian
A
Sitar
Daniel S
DS
Rexrode
Stacey
S
Zelenitsky
Sheryl A
SA
D000328:Adult; D000368:Aged; D001424:Bacterial Infections / Q000150:complications / Q000188:drug therapy; D001682:Biological Availability; D001835:Body Weight; D004334:Drug Administration Schedule; D005260:Female; D006801:Humans; D007262:Infusions, Intravenous; D007676:Kidney Failure, Chronic / Q000150:complications / Q000628:therapy*; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D008962:Models, Theoretical; D011108:Polymers; D006435:Renal Dialysis / Q000295:instrumentation / Q000379:methods*; D013450:Sulfones; D014640:Vancomycin / Q000008:administration & dosage* / Q000097:blood / Q000493:pharmacokinetics
D008567:Membranes, Artificial; D011108:Polymers; D013450:Sulfones; C017662:polysulfone P 1700; D014640:Vancomycin