Renin-angiotensin system blockade in patients with chronic kidney disease: benefits, problems in everyday clinical use, and open questions for advanced renal dysfunction.

Management of hypertension and albuminuria are considered among the primary goals of treatment to slow the progression of chronic kidney disease (CKD). Renin-angiotensin system (RAS) blockers, i.e., angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin receptor blockers (ARBs) are the main drugs to achieve these goals. Seminal studies have showed that RAS blockers present significant renoprotective effects in CKD patients with very high albuminuria. In post hoc analyses of such trials, these renoprotective effects appeared more robust in patients with more advanced CKD. However, randomized trials specifically addressing whether RAS blockers should be initiated or maintained in patients with advanced CKD are scarce and do not include subjects with normoalbuminuria, thus, many clinicians are unconvinced for the beneficial effects of RAS blockade in these patients. Further, the fear of hyperkalemia or acute renal decline is another factor due to which RAS blockers are usually underprescribed and are easily discontinued in patients with more advanced CKD; i.e., those in Stages 4 and 5. This review summarizes evidence from the literature regarding the use of RAS blockers in patients with advanced CKD.