In patients receiving Lokelma (sodium zirconium cyclosilicate), which electrolytes should be monitored?

Electrolyte Monitoring for Patients Receiving Lokelma

Primary Electrolyte to Monitor: Potassium

Patients receiving Lokelma (sodium zirconium cyclosilicate) require close monitoring of serum potassium levels to prevent hypokalemia, which can be even more dangerous than hyperkalemia. 1

Monitoring Schedule for Potassium

• Initial phase (first 48 hours): Check potassium levels at 24 and 48 hours after initiating therapy, as normalization typically occurs within 2.2 hours (median), with 84% achieving normokalaemia by 24 hours 2

• Early maintenance phase (days 2-7): If additional dose adjustments are needed, check potassium before each dose change; otherwise recheck at 3-7 days 3

• Ongoing maintenance: Monitor potassium levels at 1-2 weeks after each dose adjustment, then at 3 months, and subsequently at 6-month intervals 3

• More frequent monitoring is required for patients with:

  • Chronic kidney disease 1
  • Diabetes 1
  • Heart failure 1
  • History of hyperkalemia 1
  • Concurrent RAAS inhibitor therapy 1

Risk of Hypokalemia

• Hypokalemia developed in 10% of patients receiving 10g daily and 11% receiving 15g daily in clinical trials, with no cases in the 5g or placebo groups 2

• The incidence of hypokalemia remains low overall with appropriate monitoring 4

Secondary Electrolytes to Monitor

Sodium

• Lokelma exchanges sodium for potassium in the gastrointestinal tract, which can increase sodium load 4

• Monitor for edema, particularly with higher doses (15g daily), where edema incidence was 14% compared to 2% with placebo 2

• Caution is advised in patients who cannot tolerate sodium increases, including those with heart failure, severe hypertension, or marked edema 1

Magnesium

• While not specifically mentioned for Lokelma, patients with kidney disease receiving any form of potassium management should have magnesium monitored, as hypomagnesemia makes hypokalemia resistant to correction 3

• Hypomagnesemia is common in hospitalized patients (60-65% in critically ill patients) and can be exacerbated by kidney dysfunction 1

Bicarbonate

• Serum bicarbonate levels increased during maintenance therapy with SZC in clinical trials 5

• Monitor bicarbonate levels during maintenance phase, particularly in patients with chronic kidney disease 5

Clinical Algorithm for Monitoring

1. Baseline assessment: Obtain potassium, sodium, magnesium, bicarbonate, and renal function before initiating Lokelma 1

2. Acute phase (0-48 hours): Check potassium at 24 and 48 hours 2

3. Dose titration phase (days 3-14): Check potassium and sodium before any dose adjustments 3

4. Stable maintenance phase: Check potassium, sodium, and renal function at 1-2 weeks, 3 months, then every 6 months 3

5. If hypokalemia develops (K+ <3.5 mEq/L): Reduce or discontinue Lokelma and recheck potassium within 24-48 hours 2

Common Pitfalls to Avoid

• Failing to monitor potassium frequently enough during initial therapy can lead to undetected hypokalemia, which may be more dangerous than the original hyperkalemia 1

• Not adjusting monitoring frequency based on risk factors such as concurrent RAAS inhibitor use, heart failure, or advanced CKD can result in electrolyte complications 1

• Ignoring sodium load in patients with heart failure can lead to fluid retention and worsening clinical status 1, 2

• Not checking magnesium levels concurrently may result in refractory hypokalemia that is difficult to correct 3