What is the best way to administer calcium polystyrene sulfonate (CPS) to a patient with hyperkalemia due to kidney disease?

Optimal Administration of Calcium Polystyrene Sulfonate

Calcium polystyrene sulfonate should be administered orally at 15-30 g daily in divided doses, separated by at least 3 hours from other oral medications, with patients maintained in an upright position during administration. 1

Dosing and Administration Route

Oral Administration (Preferred)

• The standard adult dose is 15 g (60 mL) to 60 g (240 mL) of suspension daily, typically given as 15 g one to four times daily 1
• For moderate hyperkalemia (5.5-6.0 mEq/L), 15 g daily reduces serum potassium by approximately 0.64-0.68 mmol/L after 7 days 2
• For more severe hyperkalemia, 30 g daily achieves a greater reduction of approximately 0.94 mmol/L after 7 days 2
• Administer with the patient in an upright position to minimize aspiration risk 1
• The suspension may be introduced through a plastic tube into the stomach if needed 1

Critical Timing Considerations

• Separate calcium polystyrene sulfonate administration by at least 3 hours before or after other oral medications to prevent binding and reduced absorption 1
• Patients with gastroparesis require a 6-hour separation from other medications 1
• The onset of action is variable, typically taking several hours to days 3

Rectal Administration (Alternative Route)

• Rectal administration produces less effective results compared to oral administration 1
• Adult rectal dose: 30 g (120 mL) to 50 g (200 mL) every 6 hours as a retention enema 1
• Insert a soft, large-size (French 28) rubber tube approximately 20 cm into the rectum with the tip in the sigmoid colon 1
• Introduce the suspension at body temperature by gravity and retain as long as possible 1
• Follow with a sodium-free cleansing enema to remove the resin 1

Pediatric Dosing

• Use lower doses in children and infants, calculated at a rate of 1 mEq of potassium per gram of resin 1

Efficacy and Onset of Action

• Calcium polystyrene sulfonate demonstrates rapid potassium reduction within 3 days of treatment 2
• After 3 days: serum potassium decreases by 0.68-0.75 mmol/L depending on dose 2
• After 7 days: serum potassium decreases by 0.64-0.94 mmol/L depending on dose 2
• The in-vivo efficiency of sodium-potassium exchange is approximately 33% 1

Comparison with Newer Agents

• Sodium zirconium cyclosilicate demonstrates superior rapid potassium reduction compared to calcium polystyrene sulfonate, particularly in moderate to severe hyperkalemia (>6.0 mmol/L) 4
• At 2,4,24, and 48 hours, sodium zirconium cyclosilicate achieves greater potassium reduction than calcium polystyrene sulfonate 4
• By 72 hours, both agents achieve similar serum potassium levels 4
• The hyperkalemia control rate is significantly higher with sodium zirconium cyclosilicate at 4,24, and 48 hours 4

Safety Profile and Adverse Effects

Common Adverse Effects

• Constipation is the most common adverse drug reaction 2
• Gastrointestinal disorders including nausea, vomiting, and gastric irritation occur frequently 3
• Hypomagnesemia, hypocalcemia, and systemic alkalosis may develop 3

Serious Adverse Events

• Colonic necrosis and intestinal perforation are rare but life-threatening complications 3, 5, 6
• Fatal gastrointestinal injury has been reported with polystyrene sulfonate use 3
• The risk of hospitalization for serious gastrointestinal adverse events doubles with sodium polystyrene sulfonate 3
• Overall mortality rate of 33% has been reported with sodium polystyrene sulfonate 3

High-Risk Scenarios for Serious Complications

• Avoid calcium polystyrene sulfonate in patients with bowel obstruction, ileus, or slowed bowel transit time 6
• Postoperative patients with ileus are at particularly high risk 6
• Patients with renal failure have increased risk of bowel necrosis 6
• Do not use with sorbitol, as this combination dramatically increases the risk of colonic necrosis 6

Monitoring Parameters

• Serum potassium levels should be checked at baseline, day 3, and day 7 of treatment 2
• Monitor serum sodium, calcium, phosphorus, and magnesium levels, though these typically remain stable during treatment 2
• No significant changes in sodium, phosphorus, or calcium levels occur with calcium polystyrene sulfonate at doses of 15-30 g daily 2

Important Caveats and Contraindications

• Never heat calcium polystyrene sulfonate, as this may alter the exchange properties of the resin 1
• Where available, non-sodium-containing potassium binders (calcium polystyrene sulfonate) should be used for children with severe hypertension and hyperkalemia 3
• Each 60 mL of sodium polystyrene sulfonate suspension contains 1500 mg (65 mEq) of sodium, which may exacerbate hypertension and fluid overload 1
• Calcium polystyrene sulfonate contains no sodium content, making it preferable in sodium-sensitive conditions 3

Clinical Context and Alternative Agents

• Newer FDA-approved potassium binders (patiromer and sodium zirconium cyclosilicate) are now preferred for long-term hyperkalemia management due to superior safety profiles 3, 7
• Sodium polystyrene sulfonate has been associated with intestinal ischemia, colonic necrosis, and doubling of serious gastrointestinal adverse events 3
• Sodium polystyrene sulfonate should be avoided for acute hyperkalemia management due to delayed onset, limited efficacy, and risk of bowel necrosis 7
• The nonselective binding properties of polystyrene sulfonates may lead to hypocalcemia and hypomagnesemia 3

Comparative Efficacy

• Both calcium polystyrene sulfonate and sodium polystyrene sulfonate effectively reduce hyperkalemia in chronic kidney disease patients 8
• Calcium polystyrene sulfonate shows fewer side effects compared to sodium polystyrene sulfonate 8
• Sodium polystyrene sulfonate causes greater increases in diastolic blood pressure compared to calcium polystyrene sulfonate 8