What is the appropriate Lokelma (sodium zirconium cyclosilicate) dosing for a patient with serum potassium of 5.8 mmol/L and a glomerular filtration rate of 25 mL/min?

Lokelma Dosing for Potassium 5.8 and GFR 25

For a patient with serum potassium of 5.8 mEq/L and GFR of 25 mL/min (Stage 4 CKD), start Lokelma 10 g three times daily for up to 48 hours, then transition to 10 g once daily for maintenance. 1

Initial Treatment Phase (Correction Phase)

The FDA-approved dosing for initial treatment of hyperkalemia is 10 g three times daily for up to 48 hours 1. This applies regardless of renal function in non-dialysis patients. Your patient with a potassium of 5.8 mEq/L falls into the moderate hyperkalemia range where this standard dosing is appropriate.

Key evidence supporting this approach:

• In the ENERGIZE trial specifically studying patients with potassium ≥5.8 mEq/L, SZC 10 g doses (up to three doses within 10 hours) demonstrated significant potassium reductions within 2 hours 2
• Phase 3 trials showed that 10 g three times daily achieved normokalemia within 48 hours in 98% of patients 2
• Significant reductions in serum potassium were observed within 1 hour of a single 10 g dose 2

Maintenance Phase

After achieving normokalemia (typically within 24-48 hours), transition to 10 g once daily 1. This is the standard starting maintenance dose per FDA labeling.

Dose Titration Strategy

Monitor serum potassium and adjust in 5 g increments at intervals of 1 week or longer 1:

• Maintenance dose range: 5 g every other day to 15 g daily 1
• If potassium remains elevated: increase by 5 g
• If potassium drops below target range: decrease dose or discontinue

Special Considerations for Advanced CKD (GFR 25)

Your patient's GFR of 25 mL/min places them in Stage 4 CKD, which is important for several reasons:

Efficacy in advanced CKD:

• Post-hoc analysis of patients with eGFR <30 mL/min showed 82% achieved normokalemia within 24 hours during correction phase, with 100% achieving it by 72 hours 3
• During maintenance, 82% maintained normokalemia at Day 365 in the severe CKD subgroup 3
• SZC efficacy is preserved across all CKD stages 3

Important safety monitoring:

• Edema risk: Each 5 g dose contains approximately 400 mg sodium 1. Monitor for fluid retention, especially given the reduced renal function
• Adjust dietary sodium and increase diuretics as needed 1
• Watch for hypokalemia during maintenance therapy (occurred in 10-11% at higher doses in trials) 4

Critical Pitfalls to Avoid

1. Do NOT use Lokelma as emergency treatment for life-threatening hyperkalemia due to delayed onset of action 1. If the patient has ECG changes or potassium >6.5 mEq/L with symptoms, use traditional acute therapies (insulin/glucose, calcium) first.

2. Separate other oral medications by at least 2 hours before or after Lokelma administration to avoid drug binding 1

3. Avoid in severe constipation or bowel obstruction as it has not been studied in these conditions and may worsen gastrointestinal problems 1

4. Monitor for metabolic acidosis benefit: SZC has been shown to increase serum bicarbonate levels, which may provide additional benefit in CKD patients with metabolic acidosis 2, 5

Administration Instructions

Mix the entire contents of packet(s) in approximately 3 tablespoons of water, stir well, and drink immediately. Add more water to glass if powder remains, stir, and drink to ensure complete dose administration 1.