Estimation of kidney function for medication dosing in adult patients with chronic kidney disease: a practice update

Chronic kidney disease (CKD) is a major health concern with a growing disease burden and inequalities in access to treatments. Glomerular filtration rate (GFR) is accepted as the best overall measure of kidney function and is considered the most important measure for medications cleared by the kidneys. In clinical practice, equations that estimate GFR using validated prediction equations are routinely used. This practice update was developed by a Working Group comprising clinical pharmacists representing the Society of Hospital Pharmacists of Australia (SHPA) Specialty Practice streams of Nephrology, Oncology and haematology, Critical care and Infectious diseases. It is intended to provide practical recommendations for clinical pharmacists who use equations to estimate GFR for medication dosing decisions. The limitations of the various equations in use — such as the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI), the Cockcroft–Gault equation and Modification of Diet in Renal Disease — are summarised and compared to direct measures of kidney function using exogenous markers. The CKD-EPI equation is recommended to be used routinely as a primary measure of kidney function. Dose adjustments should also consider medication-specific, patient-related, and disease-related characteristics. Kidney function and the response to therapy should be continuously assessed by monitoring the signs, symptoms and disease outcomes, the emergence of adverse reactions or medication-induced disorders and use therapeutic drug monitoring (if available) to adjust doses accordingly.