What is the appropriate dosage of Kayexalate (sodium polystyrene sulfonate) for a patient with hyperkalemia?

Kayexalate (Sodium Polystyrene Sulfonate) Dosage for Hyperkalemia with K 5.8

For a patient with a potassium level of 5.8 mEq/L, the appropriate dosage of Kayexalate (sodium polystyrene sulfonate) is 15-30g orally as a single dose, which can be repeated if needed based on follow-up potassium levels. 1

Dosing Algorithm for Hyperkalemia Management with Kayexalate

Assessment of Hyperkalemia Severity

• K+ 5.8 mEq/L represents moderate hyperkalemia requiring prompt intervention
• Verify the result with a second sample to rule out pseudohyperkalemia from hemolysis 2
• Check ECG for signs of cardiotoxicity (peaked T waves, widened QRS, flattened P waves) 2

Initial Dosing for K+ 5.8 mEq/L

1. Standard adult dosing: 15-30g orally as a single dose 1

   • This corresponds to 60-120 mL of standard suspension
   • Each 60 mL contains 1500 mg (65 mEq) of sodium

2. Administration considerations:

   • Give at least 3 hours before or after other oral medications (6 hours for patients with gastroparesis) 1
   • Administer with patient in upright position to avoid aspiration 1
   • Can be given through nasogastric tube if needed

Follow-up and Dose Adjustments

• Recheck potassium levels 4-6 hours after administration 2
• If potassium remains elevated, additional doses may be given
• Total daily dose can range from 15-60g (60-240 mL) divided into 1-4 doses per day 1

Evidence-Based Efficacy

Sodium polystyrene sulfonate has been shown to effectively reduce serum potassium in patients with hyperkalemia:

• A randomized clinical trial demonstrated a mean reduction of 1.04 mEq/L compared to placebo in patients with mild hyperkalemia (5.0-5.9 mEq/L) when given 30g daily for 7 days 3
• Another study showed efficacy as secondary prevention of hyperkalemia in patients on RAAS inhibitors 4

Important Considerations and Precautions

Potential Adverse Effects

• Gastrointestinal effects: constipation, diarrhea, nausea, vomiting 2
• Electrolyte disturbances: hypokalemia, hypomagnesemia, hypocalcemia 5
• Sodium load: each 15g dose contains approximately 1500 mg (65 mEq) of sodium 1
  • May contribute to volume overload in susceptible patients 5

Alternative Options

For patients with concerns about sodium load or other contraindications to Kayexalate:

• Calcium polystyrene sulfonate may be safer in pre-dialysis patients as it doesn't induce volume overload 5
• Newer potassium binders (patiromer, sodium zirconium cyclosilicate) require less frequent dosing and have fewer drug interactions 2

Monitoring

• Monitor serum potassium, sodium, calcium, and magnesium levels
• Watch for signs of hypokalemia with repeated dosing
• Monitor volume status in patients with heart failure or fluid restrictions

Special Situations

• For rectal administration (less effective): 30-50g every 6 hours as retention enema 1
• For pediatric patients: Calculate based on 1 mEq of potassium per gram of resin 1

While newer potassium binders may offer advantages in chronic management, sodium polystyrene sulfonate remains an effective option for treating moderate hyperkalemia when dosed appropriately.