Kayexalate (sodium polystyrene sulfonate): Drug Safety Communication - FDA Recommends Separating Dosing

AUDIENCE: Internal Medicine, Nephrology, Cardiology, Pharmacy

ISSUE: FDA is recommending that patients avoid taking the potassium-lowering drug sodium polystyrene sulfonate (Kayexalate) at the same time as other medicines taken by mouth. A study found that sodium polystyrene sulfonate binds to many commonly prescribed oral medicines, decreasing the absorption and therefore effectiveness of those oral medicines. To reduce this likelihood, we recommend separating the dosing of sodium polystyrene sulfonate from other orally administered medicines by at least 3 hours. We are updating the sodium polystyrene sulfonate drug labels to include information about this dosing separation.

BACKGROUND: Sodium polystyrene sulfonate is used to treat hyperkalemia, a serious condition in which the amount of potassium in the blood is too high. It works by binding with potassium in the intestines so it can be removed from the body. Potassium is a mineral that helps the body function properly. Too much potassium in the blood can cause problems with heart rhythm, which in rare cases can be fatal. Sodium polystyrene sulfonate is available as the brand name Kayexalate, as generic brands, and also as non-branded generics.

RECOMMENDATION: Patients should take orally administered prescription and over-the-counter (OTC) medicines at least 3 hours before or 3 hours after taking sodium polystyrene sulfonate. Patients should not stop taking their potassium-lowering medicines without talking to their health care professional first. If you have questions or concerns, including about how to take sodium polystyrene sulfonate with other medicines, talk to a pharmacist or other health care professional.

When prescribing sodium polystyrene sulfonate, health care professionals should advise patients to separate dosing from other orally administered medicines by at least 3 hours. That time should be increased to 6 hours for patients with gastroparesis or other conditions resulting in delayed emptying of food from the stomach into the small intestine.

Healthcare professionals and patients are encouraged to report adverse events or side effects related to the use of these products to the FDA's MedWatch Safety Information and Adverse Event Reporting Program:

Complete and submit the report Online: www.fda.gov/MedWatch/report
Download form or call 1-800-332-1088 to request a reporting form, then complete and return to the address on the pre-addressed form, or submit by fax to 1-800-FDA-0178

[09/06/2017- Drug Safety Communication - FDA]

Previous MedWatch Alert:

[10/22/2015 - Kayexalate (sodium polystyrene sulfonate): Drug Safety Communication - FDA Requires Drug Interaction Studies]