How should GFR be assessed for drug dosing?
In its guidance to industry, the Food and Drug Administration (FDA) states that the method for assessment of kidney function that is most widely used in clinical practice ought to be the method used for adjustment of drug dosages.
At the time, the Cockcroft-Gault equation was widely used, and the FDA provided this equation as an example of an estimate that could be used. Since then, more accurate equations are now available and widely reported (i.e., CKD-EPI equation and MDRD Study equation).
The KDIGO 2011 clinical update on drug dosing in patients with acute and chronic kidney diseases recommended using the most accurate method for GFR evaluation for each patient rather than limiting the evaluation to the Cockcroft-Gault formula.
Because larger people have larger kidneys which are able to clear more drug compared with smaller people, it is recommended to express GFR as mL/min, without indexing for BSA, for dosing adjustment based on GFR.
Converting eGFR from mL/min per 1.73 m 2 to mL/min requires multiplication by BSA/1.73 m 2 .
