Hyperkalemia Associated With Inhibitors of the Renin-Angiotensin-Aldosterone System

aintenance of normal potassium homeostasis is in- creasingly an important limiting factor in the therapy of cardiovascular disease. Many pharmacological agents that reduce morbidity and mortality in patients with complicated myocardial infarction and chronic heart failure, including -blockers, angiotensin-converting enzyme inhibitors, angio- tensin-receptor blockers (ARBs), and aldosterone receptor antagonists, are also known to raise serum potassium and augment the risk of life-threatening hyperkalemia. Con- versely, loop diuretics, a mainstay of heart failure treatment, tend to enhance the risk of hypokalemia and ventricular arrhythmias, which may in part account for their consistent dose-related association with increased mortality in observa- tional studies. Because combination drug therapy may simul- taneously improve clinical outcomes and enhance the risk of potassium-related adverse events, an appropriate balance of benefit and risk depends heavily on careful patient selection and adequate surveillance of serum potassium and renal function.