August 20, 2014
  Questions About Digoxin’s Safety in Treating Atrial Fibrillation

Palo Alto, CA—Should atrial fibrillation (AF) continue to be treated with digoxin? A new study suggested the therapy be used with great care, if at all.

The study, published recently in the Journal of the American College of Cardiology, noted that patients on the digitalis derivative were 1.2 times more likely to die than comparable patients prescribed other therapies.

“The take-home point is to question whether people should really be on this drug,” said lead author Mintu Turakhia, MD, director of cardiac electrophysiology at the Veterans Affairs (VA) Palo Alto Health Care System and assistant professor at Stanford University School of Medicine. “These data challenge the current guidelines.”

The U.S. veterans study was just the latest entry into a heated international debate about the safety of digoxin in treating AF patients.

With researchers analyzing records from 122,465 VA patients who received a new diagnosis of atrial fibrillation between 2003 and 2008, digoxin was found to be prescribed to 23% of patients, with 70% remaining on the drug a year later.

Study results indicate that the increased risk of death from digoxin persisted regardless of age, use of other drugs—such as beta-blockers, amiodarone or warfarin—or comorbidities such as history of kidney disease, heart attack, or heart failure.

“This is going to be as close to proof positive as we get because we may never have a randomized trial of this drug,” Turakhia pointed out. Pharmaceutical companies lack the incentive to finance studies on a long-accepted, generic drug, he pointed out.

He suggested that digoxin has remained in the mix because physicians and patients trust the drug due to its long history. Digitalis derivatives have been in use at least since the 18th century.

“There's an evidence gap,” Turakhia said, explaining that he decided to do a review because digoxin hasn’t undergone the rigorous testing of most other atrial fibrillation treatment options.

The subsequent study overwhelmingly included male veterans—only 1.6% were female—and Turakhia suggested that additional research should try to determine if the drug has the same effect in women.

He argued that many other therapies with better safety results are available to treat atrial fibrillation compared to digoxin, which slows the heart rate but does not correct it to a normal rhythm.

“We are not asserting this drug should never be used,” Turakhia said. “However, in light of the many other drugs that can be used to slow down the heart rate in atrial fibrillation, patients and providers need to ask whether digoxin should be the treatment of choice when there are other, safer drugs.”

U.S. Pharmacist Social Connect