How can I prescribe medication for hyperkalemia?

Prescribing Medications for Hyperkalemia

For the treatment of hyperkalemia, sodium zirconium cyclosilicate (SZC) is the preferred first-line potassium binder due to its rapid onset of action, high selectivity for potassium, and favorable safety profile compared to older agents. 1, 2

Classification and Assessment of Hyperkalemia

• Hyperkalemia is classified as mild (5.0-5.5 mEq/L), moderate (5.6-5.9 mEq/L), or severe (>6.0 mEq/L) 1, 3
• Initial evaluation should include assessment of kidney function, medication review (especially RAASi medications), and ECG for severe cases 1, 3
• Repeat serum potassium measurement within 24-48 hours for mild hyperkalemia to confirm the diagnosis 3

Acute Management Options

For Severe Hyperkalemia (>6.0 mEq/L)

• Stabilize cardiac membrane with calcium chloride or gluconate (IV) 1
• Shift potassium intracellularly with:
  • Insulin (IV) with glucose 1
  • Beta-2 adrenergic agonists (nebulized) 1
  • Sodium bicarbonate (if metabolic acidosis present) 1
• Increase potassium elimination with:
  • Loop diuretics (if kidney function adequate) 1, 3
  • Potassium binders 1
  • Hemodialysis for refractory cases or severe symptoms 1

For Mild to Moderate Hyperkalemia (5.0-5.9 mEq/L)

• Review and adjust medications that increase potassium 1, 3
• Consider dietary potassium restriction 3
• Prescribe potassium binders as indicated 1, 2

Potassium Binders: Comparison and Selection

Sodium Zirconium Cyclosilicate (SZC/Lokelma)

• Dosing for initial treatment: 10g three times daily for up to 48 hours 2
• Maintenance dosing: 10g once daily, adjustable from 5g every other day to 15g daily based on serum potassium 2
• Administration: Mix powder in approximately 3 tablespoons of water, stir well and drink immediately 2
• Advantages:
  • Rapid onset of action (1 hour) 1
  • Highly selective for potassium 1
  • Acts in both small and large intestines 1
  • Effective in normalizing potassium within 48 hours (98% of patients) 4
• Cautions:
  • Contains 400mg sodium per 5g dose 1
  • Monitor for edema, especially with 15g daily dose 4
  • Separate from other oral medications by at least 2 hours 2

Patiromer (Veltassa)

• Dosing: Starting dose 8.4g once daily, titrate up to 25.2g daily as needed 1
• Onset of action: 7 hours 1
• Advantages: No sodium content (exchanges calcium for potassium) 1
• Cautions:
  • Monitor for hypomagnesemia 1
  • Separate from other medications by at least 3 hours 1

Sodium Polystyrene Sulfonate (SPS/Kayexalate)

• Dosing: 15g 1-4 times daily (oral) or 30-50g 1-2 times daily (rectal) 1
• Cautions:
  • Associated with serious gastrointestinal adverse events including intestinal necrosis 1
  • Variable onset of action (hours to days) 1
  • Poor selectivity for potassium 1
  • Contains significant sodium and sorbitol 1
  • Limited evidence supporting long-term use 1

Special Populations

Patients on Chronic Hemodialysis

• For patients on hemodialysis, administer SZC only on non-dialysis days 2
• Starting dose: 5g once daily on non-dialysis days 2
• For serum potassium >6.5 mEq/L, consider 10g once daily on non-dialysis days 2
• Maintenance dose range: 5-15g once daily on non-dialysis days 2

Patients with Chronic Kidney Disease

• Both SZC and patiromer are effective regardless of CKD stage 5
• SZC has been shown to correct hyperkalemia and maintain normokalemia in patients with advanced CKD (eGFR <30 mL/min/1.73m²) 5
• Monitor for edema with SZC, particularly in patients with fluid restrictions 2, 4

Patients on RAAS Inhibitors

• For mild hyperkalemia (K+ 5.0-5.5 mEq/L), RAASi therapy can usually be continued with close monitoring 1, 3
• For moderate to severe hyperkalemia (K+ >5.5 mEq/L), consider temporarily reducing or discontinuing RAASi therapy until potassium normalizes 1
• Newer potassium binders (patiromer or SZC) may allow continuation of RAASi therapy in patients with hyperkalemia 1, 3

Monitoring Recommendations

• For initial treatment with SZC, check potassium levels within 48 hours 2, 4
• During maintenance therapy, monitor serum potassium at intervals of 1 week or longer 2
• Monitor for hypokalemia, especially with higher doses of potassium binders 4
• For patients with edema risk, monitor fluid status when using SZC 2, 4

Common Pitfalls and Caveats

• SZC should not be used as emergency treatment for life-threatening hyperkalemia due to its delayed onset compared to IV interventions 2
• Avoid SZC in patients with severe constipation, bowel obstruction, or impaired GI motility 2
• Separate administration of potassium binders from other oral medications to prevent binding interactions 1, 2
• Consider the sodium content of SZC in patients who should restrict sodium intake 2
• Monitor for hypomagnesemia with both SZC and patiromer 1