Generic name: sodium polystyrene sulfonate (SOE dee um pol ee STEER een SUL foe nate)
Brand name: Kalexate, Kayexalate, Kionex
Drug class: Cation exchange resins

The Kayexalate brand name has been discontinued in the U.S. If generic versions of this product have been approved by the FDA, there may be generic equivalents available.

Kayexalate binds itself to potassium in your digestive tract. This helps prevent your body from absorbing too much potassium.

Kayexalate is used to treat high levels of potassium in the blood, also called hyperkalemia.

Kayexalate works differently from other medicines because it passes into your intestines without being absorbed into your blood stream.

Kayexalate may also be used for purposes not listed in this medication guide.


You should not use Kayexalate if you have low potassium levels or a bowel obstruction.

Do not give this medicine orally (by mouth) to a newborn baby.

Avoid taking other medicines by mouth within 3 hours before or 3 hours after you take Kayexalate (or 6 hours before/after if you have slow digestion).

Before taking this medicine

You should not use Kayexalate if you are allergic to it, or if you have:

  • low potassium levels (hypokalemia); or
  • a bowel obstruction.

Tell your doctor if you have ever had:

  • heart disease or high blood pressure;
  • a weak immune system caused using certain medicine;
  • severe constipation or other bowel problems;
  • kidney disease (or if you are on dialysis);
  • an electrolyte imbalance (such as low levels of potassium, calcium, or magnesium in your blood);
  • fluid retention;
  • severe burns;
  • a bowel disorder, or surgery on your intestines;
  • if you are dehydrated; or
  • if you are on a low-salt diet.

Because Kayexalate is not absorbed into the bloodstream, this medicine is not expected to be harmful during pregnancy or while nursing a baby. Tell your doctor if you are pregnant or breast-feeding.

How is Kayexalate given?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Kayexalate can be given as a liquid by mouth, through a stomach feeding tube, or as a rectal enema.

Do not give Kayexalate orally (by mouth) to a newborn baby. Do not use the medicine orally or rectally in a baby who has slow digestion caused by surgery or by using other medicines.

To give this medicine orally: Mix the Kayexalate powder with water, or with honey or jam to make it taste better. Avoid inhaling the oral powder while you are preparing a dose.

Do not mix the powder with any juice or other liquid that contains potassium, such as orange juice.

The rectal enema form of this medicine is usually given by a healthcare professional. The enema will be inserted slowly while you are lying down. You may need to hold in the enema for up to several hours. The Kayexalate enema is usually followed with a second cleansing enema.

You will need frequent medical tests to help your doctor determine how long to treat you with Kayexalate.

Keep using this medicine even if you feel fine. Hyperkalemia often has no symptoms that you will notice until your potassium levels are very low.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Use the medicine as soon as you can, but skip the missed dose if it is almost time for your next dose. Do not use two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while using Kayexalate?

Avoid using antacids or laxatives without your doctor's advice. Antacids or laxatives can make Kayexalate less effective, or cause serious side effects.

Do not use potassium supplements, calcium supplements, or salt substitutes while you are taking Kayexalate, unless your doctor has told you to.

Avoid eating or drinking anything that contains sorbitol (a fruit sugar often used as a sweetener in chewing gum, diet drinks, baked goods, or frozen desserts).

Kayexalate side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop using Kayexalate and call your doctor at once if you have:

  • stomach pain, rectal pain;
  • severe constipation, severe stomach pain, bloating;
  • fever, chills, vomiting;
  • confusion, thinking problems, feeling irritable;
  • low potassium--leg cramps, constipation, irregular heartbeats, fluttering in your chest, increased thirst or urination, numbness or tingling, muscle weakness or limp feeling;
  • low calcium levels--muscle spasms or contractions, numbness or tingly feeling (around your mouth, or in your fingers and toes); or
  • signs of stomach bleeding--bloody or tarry stools, coughing up blood or vomit that looks like coffee grounds.

Common side effects may include:

  • nausea, vomiting;
  • diarrhea, constipation; or
  • loss of appetite.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect Kayexalate?

Kayexalate can make it harder for your body to absorb medicines you take by mouth. Avoid taking other medicines within 3 hours before or 3 hours after you take this medicine.

  • If you have a condition that slows your digestion, avoid taking other medicines by mouth within 6 hours before or 6 hours after you take Kayexalate.

Tell your doctor about all your other medicines. Some may affect Kayexalate, especially:

  • digoxin, digitalis;
  • lithium;
  • thyroxine; or
  • drugs that weaken the immune system such as cancer medicine, steroids, and medicines to prevent organ transplant rejection.

This list is not complete. Other drugs may affect Kayexalate, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.