Sodium Zirconium Cyclosilicate

How it works

It is an insoluble inorganic cation exchanger that selectively traps potassium ions in exchange for hydrogen and sodium throughout the gastrointestinal tract, increasing faecal potassium excretion and lowering serum potassium.

Prescribing in practice

• It is not for emergency life-threatening hyperkalaemia because the onset is too slow — use established acute measures first and reserve this agent for ongoing control.
• It can bind co-administered oral drugs with pH-dependent solubility, so separate other oral medicines from it in time as advised in the SPC.
• Each dose adds a sodium load, which warrants caution in heart failure, hypertension or fluid overload, and it may cause oedema.

Monitoring

Monitor serum potassium during initiation and dose adjustment and periodically thereafter, watching also for hypokalaemia and signs of fluid retention.

Counselling the patient

• Take other oral medicines separated in time from this binder as instructed.
• Report ankle swelling or new breathlessness, which may indicate fluid retention.
• Attend for the blood tests used to adjust your dose.

Evidence & guidelines

Randomised trials (HARMONIZE and related studies) demonstrated dose-dependent reductions in serum potassium and maintenance of normokalaemia, supporting its use for chronic hyperkalaemia management.