What Is Lokelma (Sodium Zirconium Cyclosilicate)? Uses, Dosage, and What You Need to Know in 2026

If you or someone you care for has been prescribed Lokelma, you may have questions about what it is, why it's prescribed, and how it works. Lokelma is a relatively newer medication—approved by the FDA in 2018—and not yet as widely recognized as older drugs. This guide gives you a complete, plain-language overview.

What Is Lokelma?

Lokelma is the brand name for sodium zirconium cyclosilicate (abbreviated SZC or ZS-9), a prescription medication manufactured by AstraZeneca. It belongs to a class of drugs called potassium binders (also called cation exchange resins).

Lokelma comes as a powder in individual foil packets, available in 5 g and 10 g doses. Each packet is mixed with water and drunk immediately as a suspension. It is taken by mouth (oral) and is approved for use in adults only.

What Is Lokelma Used For?

Lokelma has one FDA-approved indication: treatment of hyperkalemia (high blood potassium) in adults. It was approved by the FDA on May 18, 2018.

Hyperkalemia means your blood contains too much potassium—specifically, a serum potassium level above 5.0 mmol/L. While potassium is an essential nutrient that supports heart, muscle, and nerve function, too much of it in the blood can cause dangerous and potentially life-threatening heart rhythm problems.

Hyperkalemia is particularly common in people with:

• Chronic kidney disease (CKD) — kidneys that don't filter properly accumulate potassium
• Heart failure — especially when treated with ACE inhibitors, ARBs, or spironolactone
• Diabetes — impaired insulin signaling and kidney function contribute to potassium buildup
• Patients on RAAS inhibitors (ACE inhibitors, ARBs, spironolactone, eplerenone) — these lifesaving drugs block the hormones that normally remove potassium

Importantly, Lokelma is not intended for emergency treatment of life-threatening hyperkalemia. It has a delayed onset and should not be used as a substitute for emergency care (like IV calcium gluconate or dialysis) when potassium is dangerously elevated.

How Does Lokelma Work?

Lokelma is a non-absorbed drug—it works in your gut without entering your bloodstream. It contains a specially engineered zirconium silicate crystal structure with microscopic pores sized to selectively trap potassium ions. As the medication passes through your small and large intestines, it captures excess potassium and exchanges it for sodium and hydrogen ions. The potassium is then eliminated from your body in your stool.

This process begins within about 1 hour of the first dose. In clinical trials, the standard starting regimen of 10 g three times daily could bring potassium to the normal range in many patients within 48 hours.

What Is the Standard Lokelma Dosage?

Lokelma dosing has two phases:

• Initial (acute) phase: 10 g three times per day (TID) for up to 48 hours to rapidly lower potassium
• Maintenance phase: 10 g once daily; dose adjusted in 5 g increments at weekly intervals based on potassium monitoring
• Maintenance range: 5 g every other day to 15 g once daily (maximum: 15 g/day)
• Dialysis patients: 5 g once daily on non-dialysis days

Mix each packet with at least 3 tablespoons (45 mL) of water in a glass. Stir until cloudy, then drink immediately. If powder remains in the glass, add more water and drink that too.

Important Warnings and Precautions

• Edema (most common side effect): Each dose contains 400 mg sodium. Monitor for swelling, especially if you have heart failure or kidney disease.
• Hypokalemia (low potassium): The drug can over-correct, driving potassium too low. Regular blood tests required.
• GI motility disorders: Do not take if you have severe constipation, bowel obstruction, or bowel impaction.
• Drug timing: Take all other oral medications at least 2 hours before or after Lokelma.

How Does Lokelma Compare to Alternatives?

Compared to patiromer (Veltassa), Lokelma acts faster (1 hour vs. several days), doesn't cause magnesium depletion, but does contain sodium. Compared to the older Kayexalate (sodium polystyrene sulfonate), Lokelma has stronger clinical evidence and fewer GI side effects. For a detailed comparison, see our Lokelma alternatives guide.

Finding Lokelma at a Pharmacy Near You

With no generic available, Lokelma isn't stocked at every pharmacy. medfinder can call pharmacies near you to check availability and text you a list of locations that have it in stock.