What is the recommended Kayexalate (sodium polystyrene sulfonate) dosage for hyperkalemia?

Kayexalate (Sodium Polystyrene Sulfonate) Dosing for Hyperkalemia of 6.3 mEq/L

For a potassium level of 6.3 mEq/L, the recommended oral dose of Kayexalate is 15-30g administered as a single dose, which can be repeated every 4-6 hours based on follow-up potassium levels. 1

Initial Assessment and Management

For hyperkalemia of 6.3 mEq/L, which is considered severe:

1. Immediate cardiac stabilization:

   • Administer calcium chloride 10% (5-10 mL IV) or calcium gluconate 10% (15-30 mL IV) over 2-5 minutes to stabilize cardiac membranes 2, 3
   • Obtain ECG to assess for signs of hyperkalemia (peaked T waves, widened QRS, flattened P waves)

2. Temporary potassium shift into cells:

   • Insulin 10 units IV with 25g glucose (50 mL of D50W) over 15-30 minutes 2
   • Consider nebulized albuterol 10-20 mg over 15 minutes 2, 3

3. Potassium removal with Kayexalate:

   • Oral dose: 15-30g mixed with 3-4 mL of water or syrup per gram of resin 1
   • Rectal dose (if oral route not feasible): 30-50g every 6 hours as retention enema 1

Kayexalate Administration Details

• Preparation: Mix with water or syrup (approximately 3-4 mL of liquid per gram of resin) 1
• Timing: Administer at least 3 hours before or after other oral medications (6 hours for patients with gastroparesis) 1
• Monitoring: Recheck potassium levels within 24 hours after administration 3

Important Considerations

Efficacy and Onset

• Kayexalate has a delayed onset of action (4-6 hours) and should not be used as the sole treatment for life-threatening hyperkalemia 1
• A single dose of 30g SPS can reduce serum potassium by approximately 0.76 mEq/L within 6-24 hours 4

Contraindications

• Avoid in patients with:
  • Obstructive bowel disease
  • Reduced gut motility
  • History of bowel necrosis or perforation 1

Monitoring Requirements

• Monitor serum potassium, calcium, and magnesium levels during therapy 1
• For patients sensitive to sodium intake (heart failure, hypertension), monitor for fluid overload as each 15g dose contains 1,500 mg (60 mEq) of sodium 1

Potential Adverse Effects

• Gastrointestinal effects: constipation, diarrhea, nausea, vomiting 2
• Electrolyte disturbances: hypokalemia, hypocalcemia, hypomagnesemia 2, 5
• Serious complications (rare): intestinal necrosis, especially when used with sorbitol 1

Follow-up Management

• Recheck serum potassium within 24 hours after initiating treatment 3
• If potassium remains elevated, additional doses may be administered
• For chronic hyperkalemia management, lower maintenance doses (15g daily or every other day) may be effective 6
• Consider addressing underlying causes of hyperkalemia (medication review, renal function assessment)

Pitfalls to Avoid

• Do not rely solely on Kayexalate for emergency treatment of life-threatening hyperkalemia due to its delayed onset of action 1
• Do not administer with sorbitol as this combination has been associated with intestinal necrosis 1
• Do not overlook the need for cardiac monitoring in severe hyperkalemia 2
• Do not forget to verify hyperkalemia with a repeat sample to rule out pseudohyperkalemia from hemolysis during blood draw 2

For patients requiring long-term management of hyperkalemia, low-dose daily Kayexalate (15g) has been shown to be effective and well-tolerated for chronic use 6, 7.