Gastrointestinal cation exchangers

Q: Which of the following has relatively a quicker action in hyperkalemia to reduce the potassium level? (select one)

A) Patiromer

B) Sodium zirconium cyclosilicate (SZC)

Answer: B

Although hemodialysis (HD) is a recommended treatment for life-threatening hyperkalemic emergency but it may require time to arrange the logistics of HD. Many patients may require insertion of hemodialysis catheter and may not be arranged quickly in many community settings. 

Gastrointestinal cation exchangers such as patiromer, sodium zirconium cyclosilicate (SZC), or sodium polystyrene sulfonate (SPS) are frequently used as an adjuvant treatment along with calcium, sodium bicarbonate and insulin/glucose combo to bridge that time.

SPS is falling out of favor due to its potential side effect of bowel necrosis. SZC is usually preferred over patiromer as it acts relatively faster. SZC (dose of 10 gram) reduces serum potassium by average of 0.37 mEq/L in four hours after the first dose.

#electrolytes

References:

1. Rafique Z, Liu M, Staggers KA, et al. Patiromer for Treatment of Hyperkalemia in the Emergency Department: A Pilot Study. Acad Emerg Med 2020; 27:54.

2. Peacock WF, Rafique Z, Vishnevskiy K, et al. Emergency Potassium Normalization Treatment Including Sodium Zirconium Cyclosilicate: A Phase II, Randomized, Double-blind, Placebo-controlled Study (ENERGIZE). Acad Emerg Med 2020; 27:475.

3. Packham DK, Rasmussen HS, Lavin PT, et al. Sodium zirconium cyclosilicate in hyperkalemia. N Engl J Med 2015; 372:222.

4. McGowan CE, Saha S, Chu G, et al. Intestinal necrosis due to sodium polystyrene sulfonate (Kayexalate) in sorbitol. South Med J 2009; 102:493.