Safety of Heart Rx Digoxin Debated

Digoxin to treat atrial fibrillation and heart failure may not increase risk of death

(RxWiki News) While digoxin helps the heart beat stronger, its safety has been debated. One study found the medication to be linked to higher mortality, but re-analysis of the data found no such connection.

Digoxin (brand name Lanoxin) helps control heart rates and is used to treat heart failure and abnormal heart rhythms, such as atrial fibrillation.

While it can help boost muscle contractions for those who have weak heart strength, digoxin also has side effects. Its effectiveness depends on getting the dosage just right.

"Research all possible side effects."

Ali Ahmed, MD, professor in the divisions of Gerontology, Geriatrics, & Palliative Care and Cardiovascular Disease at the University of Alabama at Birmingham (UAB), served as senior author on this investigation, which found no evidence that digoxin increases mortality in patients with atrial fibrillation.

Atrial fibrillation is the most common kind of cardiac arrhythmia, an electrical malfunction that throws off the heart’s rhythm and pumping rate.

Digoxin is the most commonly prescribed preparation of digitalis, which is derived from the foxglove plant and has been used to treat heart disease since the 1700s.

Researchers in two studies (both published in the European Heart Journal) examined data collected in 2002 as part of Atrial Fibrillation Follow-up Investigation of Rhythm Management (AFFIRM). At the start of the investigation, 2,153 patients were on digoxin and 1,905 patients were not.

In the first study published in late November 2012, scientists at the Gill Heart Institute at the University of Kentucky in Lexington wrote that digoxin was associated with a significant increase in mortality in patients with atrial fibrillation.

In the latest paper, Dr. Ahmed and his team observed that the higher risk of death may have inadvertently been attributed to digoxin when it was actually due to heart failure. Older patients with atrial fibrillation often have heart failure.

“When we accounted for how many patients in the digoxin group had heart failure going in, the association between digoxin and mortality disappeared,” said Dr. Ahmed.

“Our finding that digoxin does not increase mortality should reassure the field and patients about the continued use of digoxin in atrial fibrillation," said Mihai Gheorghiade, MD, professor of Medicine and Surgery at Northwestern University Feinberg School of Medicine, and an author of the new study.

The University of Alabama at Birmingham noted in a statement that digoxin has been shown to reduce—by about a third—the chances that heart failure patients will be admitted to the hospital within 30 days of first taking it.

Jason Poquette, BPharm, RPh, a pharmacist with Decisions Resources Group in Boston, told dailyRx News, "Digoxin should be used with extreme caution in patients impaired kidney function. Digoxin toxicity can occur if potassium levels drop due to certain types of diuretics."

Poquette added that other medications may impact the way the body metabolizes digoxin leading to serious complications.

"Patients should reports instances of blurry or yellow vision, black or bloody stool or mental confusion," he said. "More common side effects include nausea, vomiting and diarrhea. Patients taking digoxin should talk to their doctor or pharmacist about other medications they are taking.”

The study was first published online in April in the European Heart Journal.

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Review Date: 
April 30, 2013