What is the recommended dose of calcium polystyrene sulphonate (CPS) for treating hyperkalemia?

Recommended Dosage of Calcium Polystyrene Sulphonate for Hyperkalemia

The recommended dose of calcium polystyrene sulphonate (CPS) for treating hyperkalemia is 15-30 g per day orally, which can be administered as a single dose or divided into multiple doses. 1, 2

Dosing Recommendations

• Oral administration: 15-60 g daily, typically given as 15 g (four level teaspoons) one to four times daily 1, 3
• Rectal administration: 30-50 g every six hours when oral route is not feasible 1, 3
• Duration of therapy: Depends on severity and resistance of hyperkalemia; may be used for short-term or long-term management 1, 4
• Preparation: Suspend each dose in 3-4 mL of liquid per gram of resin (water or syrup); administer with patient in upright position 3

Efficacy of Different Dosing Regimens

• 15 g/day dosing: Decreases serum potassium by approximately 0.64-0.68 mmol/L after 3-7 days of treatment 2
• 30 g/day dosing: Produces a more significant reduction of 0.75-0.94 mmol/L after 3-7 days 2
• Long-term efficacy: Small doses (average 8 g/day) have shown effectiveness for controlling mild hyperkalemia in CKD patients over extended periods 4
• Single-dose effect: Average reduction of 0.93 mEq/L after a single dose administration 5

Monitoring and Safety Considerations

• Onset of action: Variable, typically several hours; not suitable for emergency treatment of life-threatening hyperkalemia 1, 3
• Medication timing: Administer at least 3 hours before or after other oral medications (6 hours in patients with gastroparesis) to avoid drug interactions 3
• Electrolyte monitoring: Regular monitoring of serum potassium, calcium, and magnesium is essential as CPS can affect these electrolytes 1, 6
• Common adverse effects: Gastrointestinal disorders (constipation, diarrhea, nausea, vomiting) are most common; constipation occurs in approximately 8% of patients 1, 4
• Serious adverse effects: Cases of intestinal necrosis (though less common with CPS compared to sodium polystyrene sulfonate with sorbitol) 1, 5

Advantages of CPS Over Sodium Polystyrene Sulfonate (SPS)

• Mineral metabolism: CPS does not induce hyperparathyroidism, unlike SPS which can decrease serum calcium and magnesium while increasing parathyroid hormone levels 6
• Volume status: CPS does not cause volume overload, whereas SPS can significantly elevate sodium and atrial natriuretic peptide levels 6
• Safety profile: CPS may be safer for pre-dialysis patients with hyperkalemia due to fewer effects on mineral metabolism and volume status 6

Special Considerations

• CKD patients: Particularly effective in stage 3-5 non-dialysis CKD patients with hyperkalemia 2, 4
• Contraindications: Avoid in patients with obstructive bowel disease or reduced gut motility 3
• Risk factors for adverse events: Use cautiously in patients with history of intestinal disease/surgery, hypovolemia, renal insufficiency, or constipation 3
• Alternative agents: Newer potassium binders (patiromer or sodium zirconium cyclosilicate) may be considered, especially for chronic hyperkalemia management 1

Clinical Decision Algorithm

1. For mild hyperkalemia (K+ 5.0-5.5 mEq/L): Start with 15 g/day of CPS 2
2. For moderate hyperkalemia (K+ 5.5-6.0 mEq/L): Consider 30 g/day of CPS 2
3. For severe hyperkalemia (K+ >6.0 mEq/L): Use temporary measures first (calcium, insulin/glucose, beta-agonists) followed by CPS at 30-60 g/day 1
4. For maintenance therapy: After initial correction, adjust dose based on serum potassium levels; 8-15 g/day may be sufficient for long-term control 4