**3.4 Adverse effects of RAAS blockers in DD-CKD patients**

ACE inhibitors showed several adverse effects in HDD-CKD patients. High-dose ACE inhibitors suppressed erythropoiesis and induced resistance to erythropoietin therapy in HDD-CKD patients. Occasionally, ACE inhibitors may cause anaphylactoid reactions with AN69 dialysis membrane in HDD-CKD patients by elevation of bradykinin level (Kammerl *et al.*, 2000). Hyperkalemia, which is a frequent concern in HDD-CKD patients independently of medication use, is the primary danger from RAAS blocking medications. Several clinical trials of ACE inhibitors, ARBs, and renin inhibitor in HDD-CKD patients tracked potassium levels. Increased hyperkalemia by these RAAS blockers in HDD-CKD patients was not observed in these trials. These results suggested that the risk of hyperkalemia by RAAS blocking is small.
