From the Guidelines
Angiotensin II receptor blockers (ARBs) do not typically cause hypokalemia, and in fact, may occasionally cause hyperkalemia due to their mechanism of action. According to the expert consensus document on the management of hyperkalaemia in patients with cardiovascular disease treated with renin angiotensin aldosterone system inhibitors, ARBs can increase K+ levels, and therapies aimed at lowering K+ levels should be considered to enable patients to continue ARBs therapy 1. The use of potassium binders, such as PSC (Veltassa) and SZC (ZS-9), can help normalize elevated K+ levels and prevent recurrences of hyperkalaemia in patients on ARBs therapy 1.
When initiating ARBs therapy, it is essential to monitor potassium levels closely, especially in high-risk patients, such as those with kidney disease, diabetes, or those taking potassium supplements or other medications that can raise potassium levels 1. The consensus document recommends starting ARBs therapy at a low dosage and titrating to the maximum tolerated evidence-based doses, while closely monitoring K+ levels 1.
Key points to consider when using ARBs include:
- Regular monitoring of potassium levels, especially in high-risk patients
- Starting ARBs therapy at a low dosage and titrating to the maximum tolerated evidence-based doses
- Considering potassium-lowering therapies, such as potassium binders, to enable patients to continue ARBs therapy
- Monitoring kidney function and adjusting drug doses as needed 1.
Overall, ARBs are generally considered potassium-neutral or potassium-sparing medications, and hypokalemia is not a typical side effect of these medications 1.
From the Research
Effect of ARBs on Potassium Levels
- ARBs are associated with an increased risk of hyperkalemia, particularly in patients with chronic renal insufficiency 2, 3, 4, 5.
- The use of ARBs can lead to hyperkalemia due to their effects on the renin-angiotensin-aldosterone system, which can result in reduced potassium excretion 2, 3, 4.
- Studies have shown that the risk of hyperkalemia is higher in patients with certain risk factors, such as high baseline potassium levels, reduced glomerular filtration rate, and diabetes 3, 4.
Onset Time of Hyperkalemia
- Hyperkalemia can occur shortly after initiation of ARB therapy, with one study finding that 52% of hyperkalemic events occurred within the first week of treatment 3.
- The highest frequency of hyperkalemia was found to occur on the first day after initiation of ARBs 3.
Comparison of Hyperkalemic Risk among ARBs
- A study comparing the hyperkalemic risk of different ARBs found that telmisartan had a lower risk of hyperkalemia compared to other ARBs 4.
- However, another study found that adequate intake of potassium did not cause hyperkalemia in hypertensive individuals taking medications that antagonize the renin-angiotensin-aldosterone system, including ARBs 6.
Special Populations
- In anuric hemodialysis patients, the use of ARBs was associated with an increased risk of hyperkalemia, with a significant increase in serum potassium concentrations after starting ACEi/ARB therapy 5.
- The proportion of patients with normal serum potassium concentrations decreased from 82% to 29% after starting ACEi/ARB therapy, and 19% of patients developed severe hyperkalemia necessitating treatment withdrawal 5.