Dosing of cytotoxic chemotherapy: impact of renal function estimates on dose.
BACKGROUND
Oncology clinicians are now routinely provided with an estimated glomerular filtration rate on pathology reports whenever serum creatinine is requested. The utility of using this for the dose determination of renally excreted drugs compared with other existing methods is needed to inform practice.


METHODS
Renal function was determined by [Tc(99m)]DTPA clearance in adult patients presenting for chemotherapy. Renal function was calculated using the 4-variable Modification of Diet in Renal Disease (4v-MDRD), Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), Cockcroft and Gault (CG), Wright and Martin formulae. Doses for renal excreted cytotoxic drugs, including carboplatin, were calculated.


RESULTS
The concordance of the renal function estimates according to the CKD classification with measured Tc(99m)DPTA clearance in 455 adults (median age 64.0 years: range 17-87 years) for the 4v-MDRD, CKD-EPI, CG, Martin and Wright formulae was 47.7%, 56.3%, 46.2%, 56.5% and 60.2%, respectively. Concordance for chemotherapy dose for these formulae was 89.0%, 89.5%, 85.1%, 89.9% and 89.9%, respectively. Concordance for carboplatin dose specifically was 66.4%, 71.4%, 64.0%, 73.8% and 73.2%.


CONCLUSIONS
All bedside formulae provide similar levels of concordance in dosage selection for the renal excreted chemotherapy drugs when compared with the use of a direct measure of renal function.
Department of Pharmacy, Alfred Health, Melbourne.
M J
MJ
Dooley
S G
SG
Poole
D
D
Rischin
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000970:Antineoplastic Agents / Q000008:administration & dosage* / Q000097:blood; D016190:Carboplatin / Q000008:administration & dosage* / Q000097:blood; D003404:Creatinine / Q000097:blood; D054796:Drug Dosage Calculations; D005260:Female; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D051437:Renal Insufficiency / Q000097:blood / Q000188:drug therapy* / Q000473:pathology
D000970:Antineoplastic Agents; D003404:Creatinine; D016190:Carboplatin
carboplatin; chemotherapy; dose; glomerular filtration rate; renal function