What is the management approach for a patient with impaired renal function and hyperkalemia?

From the Guidelines

Management of hyperkalemia in patients with impaired renal function requires prompt intervention based on potassium levels and symptoms, with the goal of reducing morbidity, mortality, and improving quality of life. For severe hyperkalemia (>6.5 mmol/L) or with ECG changes, immediate stabilization of cardiac membranes with IV calcium gluconate (10 mL of 10% solution over 2-3 minutes) is recommended, as suggested by the European Heart Journal study 1. Shifting potassium intracellularly can be achieved with insulin (10 units regular insulin IV with 25g dextrose) and inhaled beta-2 agonists like albuterol (10-20 mg nebulized), as outlined in the European Heart Journal study 1. Some key points to consider in the management of hyperkalemia include:

• For potassium removal, sodium polystyrene sulfonate (15-30g orally or rectally), patiromer (8.4-25.2g daily), or sodium zirconium cyclosilicate (10g TID for 24-48 hours, then 5-10g daily) can be used, as recommended by the European Heart Journal study 1.
• Loop diuretics like furosemide (40-80mg IV) may help in patients with residual kidney function, as suggested by the Mayo Clinic Proceedings study 1.
• For severe cases unresponsive to medical therapy, hemodialysis remains the definitive treatment, as stated in the European Heart Journal study 1.
• Long-term management includes dietary potassium restriction (limiting to 2-3g daily), reviewing and adjusting medications that raise potassium levels (ACE inhibitors, ARBs, potassium-sparing diuretics), treating metabolic acidosis if present, and regular monitoring of potassium levels, as recommended by the European Heart Journal study 1. The approach works by temporarily stabilizing cardiac membranes, shifting potassium into cells, and ultimately removing excess potassium from the body while addressing underlying causes, with the most recent and highest quality study guiding the management approach 1.

From the FDA Drug Label

In an open-label, uncontrolled study, 25 patients with hyperkalemia (mean baseline serum potassium of 5.9 mEq/L) and chronic kidney disease were given a controlled potassium diet for 3 days, followed by 16.8 grams patiromer daily (as divided doses) for 2 days while the controlled diet was continued. A statistically significant reduction in serum potassium (-0.2 mEq/L) was observed at 7 hours after the first dose.

The total exposure to LOKELMA in the safety and efficacy clinical trials of patients not on dialysis with hyperkalemia was 1,760 patients with 652 patients exposed to LOKELMA for at least 6 months and 507 patients exposed for at least one year.

The management approach for a patient with impaired renal function and hyperkalemia may include the use of patiromer or sodium zirconium cyclosilicate to help lower serum potassium levels.

• Patiromer has been shown to decrease serum potassium levels in patients with hyperkalemia and chronic kidney disease 2.
• Sodium zirconium cyclosilicate has also been studied in patients with hyperkalemia, but its use may be associated with an increased risk of edema 3. It is essential to monitor serum potassium levels and adjust the dose of these medications as needed to avoid hypokalemia.
• Patients on hemodialysis may require closer monitoring of their potassium levels due to the risk of hypokalemia.
• Other oral medications should be administered at least 2 hours before or after sodium zirconium cyclosilicate to minimize potential interactions.
• Patiromer may also interact with other oral medications, and administration should be separated by at least 3 hours as a precautionary measure.

From the Research

Management Approach for Impaired Renal Function and Hyperkalemia

The patient's lab results indicate impaired renal function (eGFR: 55 mL/min/1.73) and hyperkalemia (Potassium: 8.6 mmol/L). The management approach for this patient should focus on addressing the hyperkalemia and optimizing renal function.

Treatment Options for Hyperkalemia

• Patiromer and Sodium Zirconium Cyclosilicate (SZC) are two new potassium binders that have demonstrated clinical efficacy in reducing serum potassium with a good safety profile 4, 5.
• These medications can be used to manage hyperkalemia in patients with chronic kidney disease (CKD) and allow for the continuation of renin-angiotensin-aldosterone system inhibitors (RAASis) therapy 4, 6.
• Calcium gluconate, beta-agonists, and intravenous insulin can be used to stabilize cardiac membranes and shift potassium from extracellular to intracellular stores 7.
• Dialysis is the most efficient means to enable removal of excess potassium 7.

Considerations for Patients with CKD

• Hyperkalemia is a common electrolyte disorder in patients with CKD, and the risk of hyperkalemia increases as the glomerular filtration rate (GFR) declines 4, 6.
• The use of RAASis therapy can increase the risk of hyperkalemia, but discontinuation or reduction of RAASis therapy can lead to adverse cardiorenal outcomes 4, 6.
• The newer oral potassium-binding agents, patiromer and SZC, have been shown to be effective and safe for the non-emergent treatment of hyperkalemia in CKD patients, including patients treated with RAASis 6.

Comparison of Patiromer and SZC

• A recent study found no difference in effectiveness between patiromer and SZC in reducing serum potassium in patients with acute hyperkalemia 8.
• Both agents can be considered in acute hyperkalemia management, and the choice of medication should be based on individual patient factors and clinical judgment.