Potassium Could Help Heart Failure Patients

Heart failure patients taking diuretics had lower risk of death with potassium supplements

(RxWiki News) If a simple supplement could reduce the risk for death, many patients might be eager to try it. A recent study asked if potassium supplements helped heart failure patients live longer.

The researchers looked at heart failure patients taking diuretics — a type of medication that helps the body flush out salt and water.

The study found that patients who were also prescribed potassium had a reduced risk of death, especially if they were taking a higher dose of diuretics. 

"Talk to your pharmacist about the medications and supplements you take."

Doctors often prescribe patients with heart failure — which occurs when the heart is not able to effectively pump blood through the body — a type of medication called loop diuretics. These medications work to prevent a buildup of fluid that can happen in cases of heart failure.

According to the authors of this study, which was led by Charles E. Leonard, PharmD, of the Perelman School of Medicine at the University of Pennsylvania in Philadelphia, loop diuretics can sometimes cause potassium loss through urine, leading some doctors to prescribe potassium supplements.

"Potassium supplementation has been utilized over the years to offset diuretic use in patients suffering from congestive heart failure. Loop diuretics such as furosemide and bumetanide (Lasix, Bumex) have the most potential to flush potassium from the body via the kidneys, and potassium supplements have been used widely to help offset this loss," said E. Lee Carter, RPh, Clinical Pharmacy Specialist at the Department of Veterans Affairs in Prestonsburg, Kentucky.

"In recent years, with the advent of newer medications to treat [congestive heart failure] symptoms (many of which tend to be potassium-sparing), some clinicians have taken a more conservative approach to automatically prescribing potassium supplements for patients receiving diuretic therapy. Elevated potassium levels can also be a concern in patients receiving multi-drug [congestive heart failure] therapy," Carter said.

Dr. Leonard and team wanted to examine whether potassium supplementation for heart failure patients taking loop diuretics was associated with a reduced risk of death.

To do so, the researchers looked at Medicaid claims from five US states — California, Florida, New York, Ohio and Pennsylvania — between 1999 and 2007. In total, the researchers identified 654,060 heart failure patients using loop diuretics, specifically furosemide (brand name Lasix).

The patients were mostly women and had an average age of 65 years. Of these patients, 179,436 (27 percent) were prescribed potassium along with the loop diuretics.

Among the loop diuretics users, 31,653 deaths occurred during the period studied. After analyzing the data, the researchers found that those who were using potassium supplementation and had a furosemide prescription of less than 40 milligrams a day had a 7 percent reduced risk of death compared to those who were not receiving potassium. 

Those who were on a larger dose of loop diuretics — 40 milligrams or more a day of furosemide — had a 16 percent lower risk for death when they supplemented with potassium.

According to Carter, "Further study on the role of potassium in [congestive heart failure] patients is warranted. In the meantime, patients should always discuss with their primary care provider or pharmacist the results of lab studies, including their potassium levels at each appointment."

Carter added, "Patients receiving diuretic therapy should have their potassium levels and other electrolytes checked regularly. If patients experience unusual symptoms such as weakness, fatigue, muscle cramping, or irregular heartbeat, these symptoms could be a signal that their potassium level may be running low and require supplementation. Patients should seek medical attention right away should they experience any unexpected side effects."

The study was published online July 16 by PLOS ONE.

Some funding for the study was provided by the Department of Health & Human Services. Two study authors reported receiving research support or serving as consultants to a number of pharmaceutical organizations, including AstraZeneca and Bristol-Myers Squibb.

Review Date: 
July 15, 2014