Investigational Drug to Treat Hyperkalemia in Kidney Disease Patients

Within 48 hours of taking the drug, many patients saw decreased potassium levels.

The investigational drug patiromer could treat chronic kidney disease patients with elevated blood potassium-levels, a recent study indicates.

Hyperkalemia is an elevated blood potassium level above 5 millimoles per liter. This is dangerous, as it can lead to cardiac arrhythmia and sudden death. Those with chronic kidney disease (CKD), combined with diabetes and hypertension, are most at risk for hyperkalemia, as they are often treated with renin-angiotensin-aldosterone system (RAAS) inhibitors. Hyperkalemia is a possible side effect of RAAS inhibitors.

In a clinical trial from June 2011-June 2013, 300 patients from 5 different European countries were prescribed 1 of 4 doses of patiromer. The patients all suffered from CKD, as well as hyperkalemia. All were on RAAS inhibitors to treat CKD, and suffered from mild to moderate hyperkalemia.

The results found that within 48 hours of taking the drug, many patients saw decreased potassium levels. Within 4 weeks, blood potassium levels returned to normal for most patients, and sustained throughout the year long trial. At the end of 52 weeks, 90% of patients had potassium levels in the target range (3.5-5).

Patiromer is the first drug in 50 years to directly treat hyperkalemia in the United States. The current drug is 50 years old, difficult to take, and unpredictable. This is the first study using patiromer on a long-term basis, and it paves the way for further research.

"An effective treatment for hyperkalemia lets us reconsider clinical trials in more advanced kidney disease that were stopped, or never started, due to risk of hyperkalemia," stated George Bakris, MD, professor of medicine and director of the Comprehensive Hypertension Center at the University of Chicago Medicine. "Now we can evaluate the role of RAAS blockers on progression of chronic kidney disease and evaluate aldosterone blockade in heart failure patients."

Scientists are further investigating the drug’s long-term abilities. Although patients improved while on patiromer, once ending the treatment the symptoms returned within 3 days, and hyperkalemia recurred within 8 weeks.

During the trial, 14.5% of patients suffered from adverse events and 4.9% of patients died, but neither was attributed to the use of patiromer. The most common side effects of patiromer were progressing chronic kidney disease, low magnesium levels, hypertension, constipation, and diarrhea.

This study was published on July 14, 2015, in JAMA: The Journal of the American Medical Association.