What is the dose of kayexalate (sodium polystyrene sulfonate) to lower potassium levels in patients with hyperkalemia?

Kayexalate Dosing for Hyperkalemia Management

The standard adult oral dose of Kayexalate (sodium polystyrene sulfonate) for hyperkalemia is 15-60 g per day, typically administered as 15 g (four level teaspoons) one to four times daily. 1

Dosing Guidelines

• For oral administration: 15-60 g daily, given as 15 g doses (four level teaspoons) one to four times daily 1
• For rectal administration: 30-50 g every six hours as an enema 1
• One level teaspoon contains approximately 3.5 g of sodium polystyrene sulfonate and 15 mEq of sodium 1

Administration Instructions

• Oral suspension: Mix each dose in a small quantity of water or syrup (approximately 3-4 mL of liquid per gram of resin) 1
• Rectal administration: Administer as a warm emulsion in 100 mL of aqueous vehicle and flush with 50-100 mL of fluid 1
• Administer Kayexalate at least 3 hours before or 3 hours after other oral medications (patients with gastroparesis may require a 6-hour separation) 1
• Prepare suspension fresh and use within 24 hours 1
• Do not heat the suspension as it could alter the exchange properties of the resin 1

Important Limitations and Precautions

• Kayexalate should NOT be used as emergency treatment for life-threatening hyperkalemia due to its delayed onset of action (several hours to days) 2, 1
• For acute, severe hyperkalemia, more rapid-acting treatments should be used first (calcium, insulin/glucose, nebulized albuterol) 2
• Monitor serum potassium regularly during therapy as severe hypokalemia may occur 1
• Kayexalate is not totally selective for potassium and can bind other cations including calcium and magnesium, requiring monitoring of these electrolytes 2, 1
• Serious gastrointestinal adverse events including intestinal necrosis have been reported, particularly when used with sorbitol 2, 1
• Concomitant administration with sorbitol is not recommended 2

Special Populations

• Use with caution in patients with risk factors for gastrointestinal adverse events (history of intestinal disease or surgery, hypovolemia, renal insufficiency) 1
• Avoid use in patients who are at risk for developing constipation or impaction 1
• Discontinue use in patients who develop constipation 1
• For insulin-induced hyperkalemia, the ratio is 1 unit of insulin for every 4 g of glucose 3

Practical Exchange Rate

• Kayexalate has a practical exchange ratio of approximately 1 mEq potassium per 1 gram of resin 2
• Be aware that Kayexalate contains 100 mg (4.3 mmol) of sodium per 100 g of powder, which may be problematic in patients with hypertension or fluid overload 3
• Where available, non-sodium-containing potassium binders (e.g., calcium polystyrene sulfonate) should be considered for patients with severe hypertension and hyperkalemia 3

Alternative Options

• For chronic hyperkalemia management, newer potassium binders like patiromer or sodium zirconium cyclosilicate may offer more predictable onset of action and potentially better safety profiles 2
• Studies have shown that salbutamol infusion may be more effective with faster action and safer than Kayexalate for the treatment of non-oliguric hyperkalemia in preterm infants 4