Individualized drug dosage in patients treated with continuous hemofiltration.
BACKGROUND
Subtherapeutic drug dosing may be even more dangerous than overdosage, especially for intensive care patients requiring hemofiltration.


METHODS
According to Dettli's fundamental equation, body clearance of any drug (Cl) is a linear function of creatinine clearance (Cl = Cl anur + a x C(Cr)), with [a = (Cl norm - Cl anur)/C(Cr), norm]. We propose to individualize drug dosage during high-flux hemofiltration by basing it on Dettli's equation and on total C(Cr) (C(Cr) tot = C(Cr) ren + C(Cr) filt). Using this approach, drug clearance will eventually be overestimated for drugs with substantial tubular secretion and for high-efficiency hemofiltration (C(Cr) tot > 30 ml/min).


CONCLUSIONS
In patients undergoing hemofiltration, the total C(Cr) approach might be a practical alternative to standardized dosing schemes for deriving an individualized dosage from published pharmacokinetic data and functions.
Keller
F
F
Nephrology, University Hospital, Ulm, Germany. frieder.keller@medizin.uni-ulm.de
Böhler
J
J
Czock
D
D
Zellner
D
D
Mertz
A K
AK
D003401:Creatine / Q000097:blood; D006440:Hemofiltration / Q000009:adverse effects*; D006801:Humans; D008658:Inactivation, Metabolic; D010599:Pharmacokinetics; D051437:Renal Insufficiency / Q000628:therapy
D003401:Creatine