sodium zirconium cyclosilicate
Brand: Lokelma
Prototype: patiromer
Drug Class: potassium binder
Drug Family: electrolyte agent
Subclass: inorganic cation exchange compound
Organ Systems: renal
Mechanism of Action
Non-absorbed microporous zirconium silicate compound that acts as a highly selective cation exchanger in the GI lumen; preferentially traps potassium ions (over sodium, hydrogen, and calcium) in exchange for hydrogen and sodium ions throughout the GI tract, preventing potassium absorption and reducing serum potassium.
potassium ions (gastrointestinal lumen)
Indications
- hyperkalemia (acute and chronic management)
- ongoing maintenance of normokalemia in patients at risk for recurrent hyperkalemia
Contraindications
- diabetic ketoacidosis (risk of further pH disruption)
- known hypersensitivity
Adverse Effects
Common
- edema
- hypokalemia (with overdosing)
- GI adverse effects (nausea, constipation, diarrhea)
Serious
- serious edema (due to sodium exchange)
- hypokalemia
Pharmacokinetics (ADME)
| Absorption | not systemically absorbed; acts exclusively in the GI lumen |
| Distribution | confined to GI tract |
| Metabolism | not metabolized |
| Excretion | excreted in feces with bound potassium |
| Half-life | N/A (not absorbed) |
| Onset | within 1 hour for initial potassium reduction; full effect at 48 hours |
| Peak | approximately 2-4 hours for initial reduction |
| Duration | duration of action corresponds to dosing frequency |
| Protein Binding | N/A |
| Vd | N/A |
Drug Interactions
| Drug / Agent | Mechanism | Severity |
|---|---|---|
| oral medications with narrow therapeutic index | sodium zirconium cyclosilicate can bind other drugs in the GI lumen; administer other oral medications at least 2 hours before or after | moderate |
| ACE inhibitors and ARBs | may reduce hyperkalemia caused by these agents, potentially altering their tolerability and continued dosing decisions | minor |
Nursing Considerations
- Mix each packet with approximately 45 mL of water immediately before administration; administer while still in suspension — the powder does not dissolve completely, and it must not be heated.
- Monitor serum potassium frequently during the acute correction phase (every 2-4 hours in emergency settings); target correction to 3.5-5.0 mEq/L; reduce or discontinue if hypokalemia develops.
- Sodium content (approximately 400 mg sodium per 5 g dose) may contribute to fluid retention and edema; monitor for volume overload particularly in patients with heart failure or CKD.
- Administer other oral medications at least 2 hours before or after sodium zirconium cyclosilicate to prevent drug binding in the GI lumen; this interaction applies especially to narrow therapeutic index drugs.
Clinical Pearls
- Unlike sodium polystyrene sulfonate (Kayexalate), sodium zirconium cyclosilicate begins reducing serum potassium within 1 hour — making it a viable option for acute hyperkalemia management, not just chronic prophylaxis.
- The rapid onset distinguishes it from patiromer, which typically requires 7+ hours for meaningful potassium reduction; however, sodium zirconium cyclosilicate also raises serum bicarbonate slightly due to hydrogen exchange, which can be beneficial in CKD-related metabolic acidosis.
Safety Profile
Pregnancy avoid
Lactation generally-safe
Renal Adjustment Not required
Hepatic Adjustment Not required
TDM Not required
Concordance Terms
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