FDA requires Concordia Pharmaceuticals to conduct postmarketing studies
The FDA announced on Oct. 22 that it would require Concordia Pharmaceuticals, the manufacturer of sodium polystyrene sulfonate (Kayexalate), to conduct studies to investigate the drug’s potential to bind to other oral medications.
Sodium polystyrene sulfonate is used to treat patients with hyperkalemia, which occurs when there is too much potassium in the blood. Patients with hyperkalemia may have heart rhythm issues that could be fatal in rare cases. Although the labeling for sodium polystyrene sulfonate mentions it can decrease absorption of lithium and thyroxine, there have been no extensive drug-drug interaction studies performed.
The FDA noted that another potassium-lowering medication, patiromer (Veltassa), binded to approximately half of the medications tested. The labeling for patiromer, which was FDA-approved on Oct. 21, includes a warning that patients should not take other oral drugs within six hours of taking patiromer.
Prescribers and patients should also consider separating the dose of sodium polystyrene sulfonate from other oral prescription and over-the-counter medications by at least six hours, according to the FDA.
If the studies confirm significant interactions between sodium polystyrene sulfonate and other medications, the FDA said it would require manufacturers of sodium polystyrene sulfonate to update their drug labels.
Executive Editor
Tim Casey joined TriMed Media Group in 2015 as Executive Editor. For the previous four years, he worked as an editor and writer for HMP Communications, primarily focused on covering managed care issues and reporting from medical and health care conferences. He was also a staff reporter at the Sacramento Bee for more than four years covering professional, college and high school sports. He earned his undergraduate degree in psychology from the University of Notre Dame and his MBA degree from Georgetown University.