Comment on “Adopting Race‐Free Estimated Glomerular Filtration Rate for Unifying Medication‐Related Decision‐Making: An Opinion of the Nephrology Practice and Research Network of the American College of Clinical Pharmacy”

The Adult Medicine (AMED) Practice and Research Network (PRN) of the American College of Clinical Pharmacy supports adopting eGFRBSAadj for medication-related decision-making and recognizes the importance and enormity of the task. The Nephrology PRN acknowledged limited evidence to broadly substitute eGFRBSAadj for the creatinine clearance estimates (eCrCl) in historical pharmacokinetic (PK) studies, a concern shared by our members [1]. We agree that the Cockcroft–Gault (C-G) eCrCl [2] has notable flaws, and that race-free CKD-EPI eGFRBSAadj equations provide more accurate estimates of kidney function. We aim to focus on the significant barriers to implementation, including selection of the most appropriate eGFRBSAadj equation, limitations in electronic health records (EHRs), and timely cystatin C result reporting. Widespread eGFRBSAadj adoption for medication-related decision-making will require coordinated efforts, unified guidance on eGFRBSAadj use outside current U.S. Food and Drug Administration (FDA)-labeled renal dosing thresholds, and support from EHR vendors to automate calculations. Zarowitz and colleagues outlined several concerns related to substituting eGFRBSAadj for C-G eCrCl [3] in medication-related decision-making [2]. We share the concern that broadly substituting eGFRBSAadj with limited PK data may influence medication efficacy and safety. While PK evidence supporting eGFRBSAadj is growing [4], there is no data for most renally eliminated medications. We recommend proceeding carefully by prioritizing research that gives pharmacists sufficient information on the impact of eGFRBSAadj-based dosing in high-risk medications and populations. Guidance on which Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) eGFR equation to select remains nuanced, as no single equation is universally applicable, and real-time reporting of cystatin C results is limited. When cystatin C is available, the National Kidney Foundation (NKF) Workgroup recommends the 2021 CKD-EPI combined creatinine-cystatin C equation (2021 CKD-EPI eGFRcr-cys), adjusted for BSA [5]. The combined equation offers greater accuracy than equations relying on either biomarker alone [5]. The NKF Workgroup also identifies scenarios where the 2021 CKD-EPI creatinine or the 2012 CKD-EPI cystatin C equations, both adjusted for BSA, are more appropriate, particularly when non-GFR factors affect biomarker concentrations [5]. Limited access to timely and affordable cystatin C testing may hinder institutions from implementing the most accurate equation (2021 CKD-EPI eGFRcr-cys) for medication-related decision-making. To operationalize the transition, institutions should prioritize in-house cystatin C testing and standardize pharmacist guidance on CKD-EPI eGFRBSAadj equation selection. Implementing CKD-EPI equations for medication-related decision-making presents operational challenges, including adjusting laboratory-reported eGFR for each individual's BSA [5]. Manual calculations are time-intensive, error-prone, and may lead to non-standardized practices that conflict with existing pharmacist-driven protocols. Adapting EHR platforms to support eGFRBSAadj-based medication-related decision-making requires considerable institutional effort and resources, including consensus on which CKD-EPI eGFRBSAadj equation to display and use, consistent reporting of relevant laboratory data, and redesign of clinical decision alerts, screening tools, and order sets. Without investing in EHR infrastructure, workflow alignment, and education, widespread adoption of eGFRBSAadj for medication-related decision-making will be difficult to operationalize safely and consistently, which undermines the efficiency, reliability, and safety that EHRs provide. The AMED PRN supports a measured transition to eGFRBSAadj-based medication-related decision-making, recognizing that evidence, regulatory alignment, and operational barriers should be addressed before full implementation. AMED pharmacists manage diverse patient populations and regularly precept learners, uniquely positioning them to help mitigate implementation barriers. Initial steps, aligned with the considerations outlined above, include educating colleagues, providers, and learners about the transition; identifying high-risk medications where replacing C-G eCrCl with eGFRBSAadj may affect safety or efficacy; compiling evolving guidance on renal dose-adjusted medications with data directing eGFRBSAadj equation selection; advocating for timely availability of cystatin C results; collaborating with informaticists to update documentation, protocols, and decision-support tools; and conducting research to evaluate outcomes. Together, these efforts can help bridge current practice with emerging evidence, preserving patient safety while the pharmacy community accumulates robust data to guide broader evidence-informed adoption. Members of the Ad Hoc Committee: Lisa T. Hong, Tomona Iso, Nicole M. Maisch, Savannah Poole, Jennifer A. Szwak, Paul Tomkiewicz, Drew A. Wells, Emmeline M. Tran. Dhakrit (Jesse) Rungkitwattanakul for inviting the commentary and Rachel Khan for suggesting revisions. The ACCP AMED PRN convened a work group of volunteer representatives to review the Nephrology PRN publication recommending the adoption of race-free, body surface area (BSA)-adjusted estimated glomerular filtration rate (eGFRBSAadj) to standardize medication-related decision-making [1]. A draft of this letter was posted for AMED PRN membership review and comment; it reflects the broad consensus of those who responded, but we acknowledge it may not capture every viewpoint. Zotero was used for initial reference management, and Google Gemini was used to revise two sentences of the final manuscript draft. The authors declare no conflicts of interest.