Tuesday , November 21 2017
Home / Specialties / Gastroenterology / New Drug Prevents Hyperkalemia Associated with Treatment for Chronic Diabetic Kidney Disease

New Drug Prevents Hyperkalemia Associated with Treatment for Chronic Diabetic Kidney Disease

Patiromer can normalize moderate hyperkalemia, lower potassium levels in as little as 4 weeks…

 

Hyperkalemia commonly occurs in diabetes patients with hypertension or heart failure who currently take renin-angiotensin-aldosterone system (RAAS) inhibitors. RAAS inhibitors are administered in these patients to slow down the progression of kidney diseases, but it can also elevate potassium levels very quickly. Hyperkalemia can cause life-threatening cardiac arrhythmia and create sudden death.

Patiromer is composed of small beads that bind to free potassium in the lower part of the colon and promote the excretion of potassium. According to George Bakris, professor of medicine and director of the Comprehensive Hypertension Center at the University of Chicago Medicine, “[The discovery of patiromer] is a significant advance, a huge deal. [It can be used to replace] a 50-year-old drug that is difficult to take, poorly tolerated and unpredictable and most patients won’t take it.”

In a multicenter, phase 2 study, patients with hyperkalemia, hypertension, type 2 diabetes and chronic kidney disease were recruited. All patients were taking RAAS inhibitors to treat their CKD prior to and during study treatment. The mean age of participants was 66.3 years and average baseline potassium level was 5.3. The participants were taking different doses of patiromer (4.2 grams, 8.4 grams, 12.6 grams, or 16.8 grams — twice daily) based on the severity of their hyperkalemia. Potassium levels were reassessed at the end of 4 weeks of treatment.

After 4 weeks, those with mild hyperkalemia (between 5.0 mmol/L and 5.5 mmol/L) had a decrease of 0.35 at the lowest dose (4.2g twice a day), 0.5 at dose 2, and 0.55 at dose 3. Those with moderate hyperkalemia (greater than 5.5 mmol/L) had even more improvement, with decreases of 0.87 at dose 2, 0.97 at dose 3 and 0.92 at dose 4. From week 4 to week 52, serum potassium levels continued to decrease in patients with mild and moderate hyperkalemia. Over the 52 weeks, hypomagnesemia (7.2%) was the most common treatment-related adverse event, mild to moderate constipation (6.3%) was the most common gastrointestinal adverse event, and hypokalemia (<3.5 mEq/L) occurred in 5.6% of patients.

The findings “have the potential to fundamentally change the current treatment approach to hyperkalemia,” according to an accompanying editorial by nephrologist Wolfgang Winklemayer, MD, ScD, of Baylor College of Medicine. The novelty of the study, he added, “lies in the secondary results.” Potassium levels remained essentially stable throughout the maintenance phase, but after the end of the study, Winklemayer said, “potassium concentrations increased quickly and significantly, once again.”

Practice Pearls:

  • Patiromer is composed of small beads that bind to free potassium in the lower part of the colon and promote the excretion of potassium.
  • Patiromer, when given at appropriate doses based on hyperkalemia severity, is shown to normalize potassium levels and continue to lower potassium levels over the study period of 52 weeks.
  • Common side effects associated with patiromer treatment are hypomagnesemia, constipation and hypokalemia.

Bakris GL, Pitt B, Weir MR, Freeman MW, Mayo MR, Garza D, Stasiv Y, Zawadzki R, Berman L, Bushinsky DA; AMETHYST-DN Investigators. Effect of Patiromer on Serum Potassium Level in Patients With Hyperkalemia and Diabetic Kidney Disease: The AMETHYST-DN Randomized Clinical Trial. JAMA. 2015 Jul 14;314(2):151-61. doi: 10.1001/jama.2015.7446.