Lokelma vs. Kayexelate

Dr. Andrew Cox

edited by Ilyas Taraki

Background

Treatment of hyperkalemia with sodium polystyrene sulfonate (Kayexelate) is controversial, carrying high risk of bowel perforation.
The newer potassium binder sodium zirconium cyclosilicate (Lokelma), approved in 2018, does not have this risk, although it carries its own side effect profile.

Article

Beccari M, Meaney C. Clinical utility of patiromer, sodium zirconium cyclosilicate, and sodium polystyrene sulfonate for the treatment of hyperkalemia: An evidence-based review. Core Evidence. 2017;Volume 12:11-24. doi:10.2147/ce.s129555

Results

Summary of studies for Lokelma

Summary of studies for Kayexelate

Table outlining the pharmacologic properties of Kayexelate (SPS), Patiromer, Lokelma (sodium zirconium cyclosilicate)

Results Summary

Kayexalate:

3 studies
All small study sizes (all less than 100)
Measured mean potassium reduction after 24 hours - 7 days
Variable onset of action
Variable outcomes that could not be predicted based on dose
Side Effects: Hypo(all cations), constipation, nausea, vomiting, gut necrosis

Lokelma:

3 studies
Bigger study sizes (3/4 with n > 200)
Most measured change in potassium after 48 hours
Onset of action within 1-2 hours
Found predictable, dose-dependent reductions in potassium (more effective on higher K+)
“In a subgroup of patients with potassium concentrations of 6.1-7.2 mEq… produced a mean reduction of 0.4 mEq within 1 hour, and 52% of patients reached potassium of 5.5 mEq or lower within 4 hours.”
Side Effects: Less electrolyte abnormalities (better K+ affinity); however, QTc prolongation and UTIs

Limitations

No study was designed to address acute, severe hyperkalemia
None of the Lokelma studies were conducted in hospitalized patients
Exclusion of kidney transplant recipients, patients with GI disorders, or post-surgical patients
Lokelma is strictly a PO medication (Kayexalate can be given rectally)

Discussion

Further studies directly comparing Kayexalate vs. Lokelma are needed
Need to conduct further research in groups not studied (dialysis, kidney transplant, etc.)
Need to focus research on acute hyperkalemia treatment, specifically
Need to do further research on drug-drug interactions with Lokelma

References

Flinn RB, Merrill JP, Welzant WR. Treatment of the oliguric patient with a new sodium-exchange resin and sorbitol. New England Journal of Medicine. 1961;264(3):111-115. doi:10.1056/nejm196101192640302

Scherr L, Ogden DA, Mead AW, Spritz N, Rubin AL. Management of hyperkalemia with a cation-exchange resin. New England Journal of Medicine. 1961;264(3):115-119. doi:10.1056/nejm196101192640303