CLINICAL NEPHROLOGY: Edited by David S. GoldfarbRenin–angiotensin system inhibition in advanced chronic kidney disease how low can the kidney function go?Shah, Roopaa; Sparks, Matthew A.a,bAuthor Information aDivision of Nephrology, Department of Medicine, Duke University School of Medicine bRenal Section, Durham VA Medical Center, Durham, North Carolina, USA Correspondence to Dr Matthew A. Sparks, MD, Division of Nephrology, Department of Medicine, Duke University School of Medicine, Room 1013 MSRB2, 2 Genome Court, Durham, NC 27710, USA. Tel: +1 919 684 9737; fax: +1 919 684 3011; e-mail: firstname.lastname@example.org Current Opinion in Nephrology and Hypertension: March 2019 - Volume 28 - Issue 2 - p 171-177 doi: 10.1097/MNH.0000000000000484 Buy Metrics Abstract Purpose of review To present the available data on the risks and benefits for ACEi/ARB usage in patients with advanced CKD. Recent findings It has been well established that ACEi/ARB use is beneficial in patients with mild-to-moderate CKD, especially in patients with proteinuria. The majority of available data includes patients with diabetes mellitus. However, data in individuals with advanced CKD are limited. Additionally, data available for this subset of patients is conflicting and the definition of advanced CKD varies across clinical trials. Summary On the basis of our literature review, evidence suggests continuing ACEi/ARB therapy in patients with advanced CKD (eGFR less than 15 ml/min/1.73 m) unless hyperkalemia ensues unresponsive to therapy, hypotension develops or have unusually rapid worsening of eGFR (not usual progressive decline). These patients should be monitored closely. There is not enough data to support starting ACEi/ARBs de novo in patients with advanced CKD (eGFR less than 15 ml/min/1.73 m). If RAS blockade is started de novo in this subgroup, we recommend close monitoring. Copyright © 2019 Wolters Kluwer Health, Inc. All rights reserved.