Renal Function Equations and Medication Dosing: The Daily Clinical Dilemma

In 1976, Donald Cockcroft and M. Henry Gualt published a formula that estimates creatinine clearance. This study involved only Caucasian males and was done prior to the development and standardization of the modern creatinine assays. With the major advances in medicine and nephrology that have occurred over the past half century, it seems almost inconceivable that we would still be using this formula as the standard for medication dosing, yet this is the clinical reality. We explore the tension between guidelines that suggest using eGFR for medication dosing and the practical reality of our current system and the knowledge gaps that have led to continued reliance on this formula.