Digoxin Side Effects May Increase Risk of Death: Study

The findings of a new study suggest that side effects of the heart drug digoxin may reduce the lifespan of patients with atrial fibrillation, increasing the risk of death among users. 

Stanford researchers are warning doctors to be cautious about prescribing digoxin as an atrial fibrillation (AF) treatment in a study published this month in the Journal of the American College of Cardiology.

This is at least the third such major study in recent years to tie the digoxin side effects to an increased risk of death among users.

Researchers used data from The Retrospective Evaluation and Assessment of Therapies in AF (TREAT-AF), which was conducted by the U.S. Department of Veterans Affairs. The data included information on 122,465 patients, nearly 29,000 of whom were prescribed digoxin.

The study found that those prescribed digoxin were 26% more likely to die over a four year period than those not given the drug. That translated to 95 deaths per 1,000 person-years for those given digoxin, compared with 67 per 1,000 person-years among those not given the heart drug.

Researchers adjusted their findings to account for drug adherence issues, kidney function, cardiovascular problems and concomitant therapies.

“These findings challenge current cardiovascular society recommendations on use of digoxin in AF,” the researchers concluded.

Researchers from the United Kingdom came to similar conclusions in a study published in the European Heart Journal in November 2012. That study looked at 4,000 patients, and found that there was a 41% increased risk of death among AF patients given the digoxin.

In a study published in June 2010, side effects of digoxin were linked to an increased risk of death among patients undergoing dialysis treatment, with the findings suggesting that the risk was dose-related, with higher rates of death found among dialysis patients given hire doses of the drug.

More recently, a study published in the medical journal Circulation: Cardiovascular Quality and Outcomes in September 2013, researchers from Kaiser Permanente found that heart failure patients given digoxin were more likely to die than other patients.

Digoxin is commonly used to treat congestive heart failure, abnormal heart rhythms, atrial flutter and atrial fibrillation.  The medication is extremely dose-specific with a narrow therapeutic index. If too little of drug is prescribed it can be ineffective, and if too much is prescribed, it can lead to a digoxin overdose, where the drug builds up in the system. This can result in a serious and potentially life-threatening condition known as digitalis toxicity.

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.