Hypertension guidelines — such as the Canadian Hypertension Education Program (CHEP) — recommend agents affecting the Renin-Angiotensin-Aldosterone System (RAAS), as the best choice for controlling blood pressure (BP) in patients with chronic kidney disease. Hyperkale­mia and renal dysfunction are important risks with such agents and close monitoring for development of hyperkalemia is required, especially when initiating therapy. It’s important to consider the risk-benefit ratio, as low-grade hyperkalemia can often be controlled with dietary modification. Multiple agents are commonly required to control BP to target. Often, addition of a diuretic (hydrochlorothiazide, if GFR > 45-60 or furosemide if GFR < 45-60 ml/min) is helpful in controlling serum potassium and blood pressure. Avoid potassium-sparing diuretics in such cases.

It’s also vital to educate the patient to avoid high-potassium foods, especially when a diuretic is prescribed with an ACE inhibitor/ARB, as often the pharmacist provides patients with pre-printed information that advises them to consume potassium-rich food such as a banana. In some cases, chronic use of low-dose sodium polystyrene sulfonate may be required. If, however, serum potassium remains persistently high, then a calculation of risk and benefit may indicate that these agents need to be withdrawn. It’s a good idea to refer such patients to a nephrologist and renal dietitian before stopping these agents permanently and sacrificing their reno-protective benefits.