FDA Warning on Atrial Fibrillation Drug Multaq

July 22, 2011 -- If you're taking the atrial fibrillation drug Multaq, the FDA wants you to call your doctor right away.

Don't stop taking the drug -- that could be dangerous. But the FDA wants patients to be aware that a clinical trial of Multaq, called PALLAS, was halted when the drug doubled the risk of death, stroke, and heart failure hospitalization in heart patients with permanent atrial fibrillation.

Multaq is approved to treat paroxysmal atrial fibrillation (intermittent), persistent atrial fibrillation, or atrial flutter. The big question -- now the subject of an FDA investigation -- is exactly how the PALLAS findings apply to current patients.

Multaq was approved in 2009 after the ATHENA clinical trial showed it decreased deaths in patients with non-permanent atrial fibrillation and atrial flutter.

But this is now the fifth time the FDA has reported signals of possible risk from Multaq:

• Early 2010: The FDA warned of possible signals of congestive heart failure. On Feb. 22, 2011, the FDA revised the warning section of the Multaq label to note cases of worsening heart failure in some patients taking the drug.
• Second quarter 2010: The FDA warned of possible signals linking Multaq to a form of heart arrhythmia called torsade de pointes.
• Third quarter 2010: The FDA warned of possible signals that Multaq interacted with warfarin to increase warfarin's anti-clotting effect. On March 21, 2011, the FDA changed the drug-interactions section of the Multaq label to reflect this possibility.
• In the last three months of 2010, there were possible signals linking Multaq to liver failure. On Feb. 11, 2011, FDA changed the warnings section of the Multaq label to note that the drug should be stopped if liver injury is suspected.

The FDA is telling patients:

• Talk to your health care professional about whether you should continue to take Multaq for paroxysmal or persistent atrial fibrillation. Do not stop taking Multaq without talking to your health care professional.
• Discuss any questions or concerns about Multaq with your health care professional.
• Report any side effects you experience to the FDA MedWatch program (800-332-1088).

The FDA is telling doctors:

• Do not prescribe Multaq to patients with permanent atrial fibrillation.
• The FDA is evaluating whether and how the preliminary results of the PALLAS study apply to patients taking Multaq for paroxysmal atrial fibrillation, persistent atrial fibrillation, or atrial flutter.
• The PALLAS study results are considered preliminary at this time.