Sodium polystyrene sulfonate interferes with many oral drugs and should be dosed separately.
The FDA is recommending that patients be told not to take sodium polystyrene sulfonate (Kayexalate) at the same time as other oral medications. The new recommendation is based on a study that found that the drug binds with many commonly used oral medications and reduces their effectiveness.
Sodium polystyrene sulfonate is used to treat hyperkalemia. It lowers blood potassium levels by binding with potassium in the intestines and is then eliminated from the body. Side effects of hyperkalemia include cardiac arrhythmia.
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Patients should be advised to take sodium polystyrene sulfonate at least 3 hours before or after other oral drugs, including OTCs. Any patients with gastroparesis or other conditions that slow the transit of food from the stomach to the small intestine should be told to separate doses of sodium polystyrene sulfonate by 6 hours. Patients should also be told not to stop taking any potassium-lowering drugs without talking to their health-care professional first.
Sodium polystyrene sulfonate is also available under the brand names Kalexate and Kionex, as well as unbranded generic versions.