Potassium binders after transplant

Elena Nazvitch, Clinical Pharmacist

Potassium is an important mineral in your body that makes your muscles and nerves function. The kidneys help regulate the amount of potassium in your body. In patients with kidney disease, the kidneys are not working well in regulating the potassium level. A high level of potassium is dangerous and can cause the heart to not function well or stop.

Even after transplant, some patients may still have elevated potassium. Medications that are used after kidney transplant and are required either for the safety of your kidney, to prevent an infection or to control your blood pressure, can also elevate the potassium in your body. This is why the clinic keeps a close eye on your potassium levels after transplant, and if changes in diet alone are not working to reduce the potassium, your doctor may prescribe a medication to help lower the level.

There are several medications that are currently available for treatment of high potassium that may be prescribed to you. These include Calcium Polystyrene sulfonate and Sodium Polystyrene Sulfonate; they are usually given multiple times per day depending on the potassium level. A few years ago, two new medications for lowering potassium, Patiromer sorbitex calcium and sodium zirconium cyclo- silicate, have also become available and are usually given once daily to control potassium levels.

Please see below for a quick review on the newer potassium binders that you may see prescribed by our clinic:

Sodium zirconium

(Lokelma®) powder for suspension

How does it work?

Sodium zirconium cyclosilicate binds to potassium in the gastrointestinal tract in exchange for hydrogen and sodium, making less potassium available to be absorbed into your body and therefore, lowering the amount of potassium in your blood.

How do I take this medication?

This medication comes in 5 grams and 10 grams sachets. Your doctor will let you know what specific dose you will be taking.

• empty the contents of the entire sachet into a drinking glass containing approximately 45 ml of water, still well and drink immediately while the powder is suspended. The powder will not dissolve in the water and will appear like a cloudy liquid.

• if the powder settles, stir it again and drink the entire dose.

How do I store it?

Lokelma® should be stored at 15-30°C and taken immediately after reconstitution.

Are there any drug interactions?

There are medications that interact with sodium zirconium cyclosilicate. Please speak to your pharmacist about your specific medications. In general, we recommend taking this medication at least 2 hours before or after your other oral medications.

Patiromer is a calcium-sorbitol complex that binds to potassium in the gastrointestinal tract, making less potassium available to be absorbed into your body and therefore, lowering the amount of potassium in your blood.

Patiromer comes in 8.4 grams, 16.8 grams and 25.2 grams packet. Your doctor will let you know what specific dose you will be taking.

• empty the contents of the entire packet into approximately 40 ml of water and stir

• another approximately 40 ml of water should be added to the mixture as needed

• drink the mixture immediately after stirring. If any powder remains in the glass after drinking, add more water, stir and drink until you take the entire dose

• the mixture should be used within 1 hour

• you can use apple or cranberry juice instead of water if you prefer. Do not use other liquids. Do not use hot liquids

The patiromer powder should be stored refrigerated at 2-8°C. If stored in room temperature (1525°C), it needs to be used within 6 months. The reconstituted suspension should be kept in room temperature and used within 1 hour.

There are medications that interact with patiromer. Please speak to your pharmacist about your specific medications. In general, we recommend taking this medication at least 3 hours before or after your other oral medications.

Like other medications, potassium binders have side effects, which may not make them suitable for every patient. Your transplant team will decide if they are right for you based on your history and your other medical conditions.

The new potassium binders are also costly. You can speak to your transplant pharmacist about options for coverage.

April is BeADonor Month in Ontario. Our goal during BeADonor Month is to inspire those who have not yet registered consent for organ and tissue donation to join the more than four million Ontarians who have already registered. Registering gives hope to the almost 1,400 Ontarians currently waiting for a lifesaving transplant and takes less than two minutes at beadonor.ca.