Medications used to control heart rate and rhythms in individuals with atrial fibrillation may raise the risk for fainting and falls, especially in the elderly, researchers say. 

Over a 15-year period, Danish researchers examined records for 100,935 atrial fibrillation patients age 65 and older who were prescribed heart rate lowering and anti-arrhythmic drugs. 

The study showed use of antiarrhythmic drugs, either used singly or in combination with heart rate lowering drugs, was linked to higher risk of falls, fainting and related injuries, which primarily involved fractures and minor head injuries.

The risk for fainting and falls was greatest within the first 14 days of taking the medication. 

Adverse outcomes were primarily driven by the drug amiodarone, the researchers noted. Further studies are needed to determine whether specific dosing of amiodarone impacts fall and fainting risks, they added.

Atrial fibrillation in the elderly is common and often seen in more frail individuals. Falls are the leading cause of fatal and non-fatal injuries for seniors. One in four Americans age 65 and older falls each year and every 19 seconds an older adult dies from a fall, according to the Centers for Disease Control and Prevention.

The study was published in the Journal of the American Geriatrics Society.