Patiromer

How it works

It exchanges calcium for potassium in the lumen of the gastrointestinal tract, predominantly the colon, increasing faecal potassium excretion and thereby lowering serum potassium.

Prescribing in practice

• Separate patiromer from other oral medicines by several hours because it can bind co-administered drugs in the gut and reduce their absorption.
• It is not for emergency treatment of life-threatening hyperkalaemia owing to its delayed onset of action.
• It can lower serum magnesium and cause gastrointestinal effects such as constipation; review concomitant potassium-raising therapy and dietary potassium.

Monitoring

Monitor serum potassium and magnesium during treatment and after any dose adjustment, with more frequent checks when renin-angiotensin therapy is changed.

Counselling the patient

• Take other medicines separated from this one by a few hours as advised.
• Do not heat the medicine and mix the powder with water as instructed before taking.
• Continue with any prescribed low-potassium diet and report constipation.

Evidence & guidelines

Trials including OPAL-HK and AMETHYST-DN showed patiromer lowers and maintains normal serum potassium and can enable continued renin-angiotensin-aldosterone inhibition; it is recommended by NICE in specified hyperkalaemia settings.