Comparative Evaluation of the Cockcroft‐Gault Equation and the Modification of Diet in Renal Disease (MDRD) Study Equation for Drug Dosing: An Opinion of the Nephrology Practice and Research Network of the American College of Clinical Pharmacy

Abstract

Accurate assessment of kidney function is an important component of determining appropriate drug dosing regimens. Nearly all manufacturer-recommended dosage adjustments are based on creatinine clearance ranges derived from clinical pharmacokinetic studies performed during the drug development process. The Cockcroft-Gault (CG) equation provides an estimate of creatinine clearance and is the equation most commonly used to determine drug dosages in patients with impaired kidney function. The Modification of Diet in Renal Disease (MDRD) study equation has also been proposed for this purpose. Published studies report that drug dosages determined by the two equations do not agree in 10-40% of cases. However, interpretation and comparison of these studies are complicated by the variable creatinine methods used for calculating CG and MDRD estimates, the patient populations studied, and a lack of outcomes data demonstrating the clinical significance of dosing discrepancies. Moreover, the impact of reporting standardized serum creatinine values on the accuracy of the CG equation and corresponding drug dosing regimens have been questioned. Currently, no prospective pharmacokinetic studies have been conducted with use of the MDRD equation to generate dosing recommendations, and limited data are available to support its use in some patient populations representing demographic extremes. Collectively, these issues have resulted in considerable confusion among clinicians and have fueled a healthy debate on whether or not to use the MDRD equation to determine drug dosages. Each of these issues is reviewed, and a proposed algorithm for using creatinine-based kidney function assessments in drug dosing is provided. Knowledge of the advantages, limitations, and clinical role of each equation will facilitate their safe and effective use in drug dosing.

Pharmacotherapy in Chronic Kidney Disease Patients Presenting With Acute Coronary Syndrome

“…22 Although these equations have limitations, both the CG and MDRD equations have been shown to correlate relatively well with measured glomerular filtration rate (GFR), 22 but differences in medication dose recommendations have been reported depending on which equation is used. [23][24][25] An analysis of the Can Rapid Risk Stratification of Unstable Angina Patients Suppress Adverse Outcomes With Early Implementation of the ACC/AHA Guidelines (CRUSADE) registry was conducted to compare the CG and MDRD equations with regard to the recommended doses of eptifibatide, tirofiban, and enoxaparin.…”

Development and Assessment of a Nomogram to Propose the Initial Dosage Regimen of a Meropenem Infusion Based on Serum Creatinine and Age Using a Monte Carlo Simulation

“…If pharmacists calculate a dosage regimen on which to start MEPM treatment on the basis of an individual patient's data (age, sex, eGFR, sCr and BW), they may overestimate renal function as a result of using an eGFR value. 13,14) And in acute situations, the correct dose needs to be administered even when there is no possibility of directly weighing the patient. It was therefore decided to develop a convenient, user-friendly dosing nomogram to use when elderly patients are admitted to hospital with an acute infection such as CAP and need to be started on MEPM immediately.…”

Adaptation posologique des médicaments et fonction rénale : quel(s) estimateur(s) faut-il choisir ?

“…Les moindres performances de la formule de Cockcroft, auxquelles s'ajoutent des problé matiques analytiques spé cifiques lié es à l'absence de ré é valuation de cette formule avec les nouveaux dosages de cré atinine (voir infra) expliquent que cette formule n'a plus sa place dans les recommandations pour l'estimation du DFG au cours de la MRC. Malgré cela, il persiste indiscutablement un dé bat sur l'utilité de cette formule dans le champ spé cifique de l'adaptation posologique, notamment au sein de la communauté pharmacologique [2,26,33,45,46]. En effet, tout d'abord, il faut bien constater le poids historique indé niable de l'é quation de Cockcroft.…”

“…En effet, tout d'abord, il faut bien constater le poids historique indé niable de l'é quation de Cockcroft. L'immense majorité des publications sur l'adaptation posologique des mé dicaments ont, de fait, utilisé la formule de Cockcroft ou la clairance de cré atinine (pourtant elle aussi dé crié e aujourd'hui pour l'estimation du DFG) [33,[45][46][47]. Jusqu'en 2008, la formule de Cockcroft é tait d'ailleurs encore la seule à être recommandé e par la FDA [7] pour les é tudes visant à dé finir l'adaptation posologique des mé dicaments [26,47].…”