Effect of ARBs on Potassium Levels

Mechanism of Action

The American College of Cardiology notes that ARBs block the renin-angiotensin-aldosterone system (RAAS), reducing aldosterone production and decreasing potassium excretion by the kidneys, leading to potential potassium retention 1, 2
The mechanism of ARBs is similar to that of ACE inhibitors, though some evidence suggests ARBs may have a slightly smaller magnitude of potassium elevation compared to ACE inhibitors in people with nephropathy 3

Impaired renal function, especially eGFR <30 mL/min/1.73m², is a risk factor for hyperkalemia with ARBs, according to the American Heart Association 4
Concomitant use of other RAAS inhibitors, such as ACE inhibitors or aldosterone antagonists, increases the risk of hyperkalemia with ARBs, as reported by the American College of Cardiology 1, 5
Diabetes mellitus is a risk factor for hyperkalemia with ARBs, as stated by the American Heart Association 4
Advanced age is a risk factor for hyperkalemia with ARBs, according to the American Heart Association 4
High potassium intake through diet or supplements increases the risk of hyperkalemia with ARBs, as noted by the American Heart Association 2, 6
Use of other medications that can increase potassium, such as NSAIDs or COX-2 inhibitors, increases the risk of hyperkalemia with ARBs, as reported by the American Heart Association 2, 6
Volume depletion or dehydration increases the risk of hyperkalemia with ARBs, according to the American College of Cardiology 5

The American College of Cardiology recommends checking serum potassium and renal function within 1-2 weeks after initiation of ARB therapy, and rechecking after any dosage increase 2, 7
The American Heart Association suggests monitoring potassium and renal function at least every 3 months for stable patients, and more frequently for patients with risk factors for hyperkalemia 2, 5, 6

The American College of Cardiology notes that hyperkalemia risk increases when ARBs are combined with other RAAS inhibitors 1, 5
The routine triple combination of ACE inhibitors, ARBs, and aldosterone antagonists should be avoided due to significantly increased hyperkalemia risk, as reported by the American College of Cardiology and the American Heart Association 1, 4, 5

The American Heart Association recommends starting ARBs at low doses and titrating gradually with careful monitoring, to minimize the risk of hyperkalemia 4
Reducing or discontinuing potassium supplements when initiating ARBs can help minimize the risk of hyperkalemia, as noted by the American College of Cardiology and the American Heart Association 5, 6
Educating patients to avoid high-potassium foods and over-the-counter potassium supplements can help minimize the risk of hyperkalemia, according to the American Heart Association 4
Consider reducing ARB dose or discontinuing therapy if potassium levels exceed 5.5 mEq/L, as recommended by the American College of Cardiology and the American Heart Association 2, 5
Temporarily discontinuing ARBs during episodes of diarrhea, dehydration, or when loop diuretic therapy is interrupted can help minimize the risk of hyperkalemia, as noted by the American College of Cardiology and the American Heart Association 5, 6

In diabetic patients with nephropathy, close monitoring of potassium is essential, as they are at higher risk for hyperkalemia when using ARBs, according to the American Diabetes Association 3
In elderly patients, who may have decreased renal function not reflected by serum creatinine alone, more careful monitoring is warranted, as reported by the American College of Cardiology 5