Scientists have questioned whether patients should be treated with the heart drug digoxin after new evidence suggests that it increases death rates.
A study of more than 122,000 Americans with an abnormal heart rhythm, showed that those given digoxin were 20% more likely to die than patients receiving different treatments.
Two years ago a US trial involving 4,000 AF patients associated digoxin treatment with a 41% increase in deaths. Digoxin is derived from the poisonous foxglove plant, also known as digitalis, which has been used to treat heart conditions since the 18th century.
The drug, which slows heart rate and increases the force of heart contractions, is widely prescribed for heart failure and rhythm disorders.
US researchers analysed the records of 122,465 patients diagnosed with AF between 2003 and 2008.
Doctors prescribed digoxin to 23% of the patients, 70% of whom were still taking it one year later.
They were 1.2 times (20%) more likely to die than similar patients on other therapies.