Digoxin Side Effects May Increase Risk of Death In Patients With Atrial Fibrillation

Duke University researchers indicate that they have uncovered more findings that suggest the side effects of digoxin may cause an increased risk of death among individuals with atrial fibrillation. 

In a study published this month in the Journal of the American College of Cardiology, researchers found that the higher the amount of digoxin in an atrial fibrillation patient’s bloodstream, the higher their risk of death, regardless of whether they suffered heart failure.

Researchers looked at the association between digoxin and mortality in nearly 18,000 patients, finding that baseline digoxin use was not linked with an increased risk of death. However, the study’s findings indicate that patients with a serum digoxin concentration equal to or greater than 1.2 ng/ml had a 56% increased risk of death, compared with those not on the drug. The study also found that every 0.5-ng/ml increase in serum digoxin concentration was linked with a 19% higher risk of death, regardless of the atrial fibrillation patient suffered from heart failure.

“In patients with AF taking digoxin, the risk of death was independently related to serum digoxin concentration and was highest in patients with concentrations ≥1.2 ng/ml,” the researchers concluded. “Initiating digoxin was independently associated with higher mortality in patients with AF, regardless of heart failure.”

Digoxin Heart Risks Found In Numerous Studies

A dose-response relationship is often seen as a strong indicator of causality between digoxin and the risk of death. Additionally, the findings back up those of a series of similar studies in recent years.

In May 2015, a study published in the European Heart Journal found that digoxin use was linked to an increased risk of death among all heart failure patients, but found that patients with atrial fibrillation were particularly at risk.

Another study, published in March 2015, again by Duke University researchers, found that atrial fibrillation patients given digoxin along with the blood thinner Xarelto found a 17% increased risk in all-cause mortality for patients given both drugs. The risk of sudden death alone increased 36% for Xarelto patients given digoxin, compared to patients given Xarelto alone.

In November 2014, a study published by the medical journal Circulation: Arrhythmia and Electrophysiologyfound that AF patients faced a 71% higher risk of death and a 63% higher risk of hospitalizationwhen given digoxin.

In September 2014, researchers from Duke University found that digoxin increased the risk of death by 22% in patients with atrial fibrilliation. That study was presented at a conference in Barcelona, and researchers said that there need to be extensive randomized clinical trials to determine the risks and benefits of digoxin.

Another study published in the Journal of the American College of Cardiology found that atrial fibrillation patients given digoxin along with the blood thinner Xarelto found a 17% increased risk in all-cause mortality for patients given both drugs. The risk of sudden death alone increased 36% for Xarelto patients given digoxin, compared to patients given Xarelto alone.

In November 2014, a study published by the medical journal Circulation: Arrhythmia and Electrophysiologyfound that AF patients faced a 71% higher risk of death and a 63% higher risk of hospitalizationwhen given digoxin.

In September 2014, researchers from Duke University found that digoxin increased the risk of death by 22% in patients with atrial fibrilliation. That study was presented at a conference in Barcelona, and researchers said that there need to be extensive randomized clinical trials to determine the risks and benefits of digoxin.

Digoxin has what is called a narrow therapeutic window, meaning that levels in the blood must fall into a precise range for it to work and to be safe for patients. Too much can cause heart problems resulting in death and too little can be ineffective, which may also cause death.

In April 2008, Actavis Totowa issued a Digoxin recall for all lots of its generic version, Digitek, after it was discovered that some tablets may have been commercially released that were twice as thick as they were supposed to be. The error potentially exposed thousands of users to a risk of digoxin overdose or poisoning.

According to a December 2008 report released by the non-profit Center for Public Justice, the FDA received reports of at least 667 digoxin overdose deaths tied to the recalled pills between April 2008 and June 2008.