Pharmacy Services Alerts
Sodium Polystyrene Sulfonate (Kayexalate) Should be Dosed Separately From Other Oral Medications
Sep 12, 2017 9:30 AM
Sodium polystyrene sulfonate, known by the brand name Kayexalate, binds to commonly used oral medications, decreasing their absorption and potentially their effectiveness. In October 2015, FDA published a Safety Alert and required the manufacturer of Kayexalate to conduct interaction studies to determine whether Kayexalate affects other oral medications. The results of this study showed that Kayexalate significantly decreased the absorption of orally administered amlodipine, amoxicillin, furosemide, metoprolol, phenytoin, and warfarin. FDA believes it is likely that Kayexalate binds to many other oral medications, which could decrease the effectiveness of those medications. Kayexalate is used to treat hyperkalemia and is available as brand name Kayexalate, generic sodium polystyrene sulfonate, and non-branded generics (eg, Kionix).
FDA is updating the product labeling of all sodium polystyrene sulfonate products with instructions to separate the dosing of these products from other orally administered medications by at least 3 hours (before or after). This interval is based on the anticipated time it takes for drugs to pass through the stomach. Health care professionals should educate patients on this new administration recommendation and should consider recommending longer intervals (ie, 6 hours) for patients with slowed gastrointestinal transit (eg, gastroparesis). Patients should not stop taking sodium polystyrene sulfonate products without consulting with their prescriber since hyperkalemia can be life-threatening.
More information is available at the following links:
- FDA Medwatch Alert – September 6, 2017
- FDA Safety Alert – September 6, 2017
- FDA Safety Alert – October 22, 2015