FDA Updates Safety Information for Multaq

December 20, 2011 — People who take Multaq (dronedarone) to treat heart arrhythmia should be aware that the FDA is updating the safety labeling following the results of a study, which found that patients have a doubled risk of serious, life-threatening cardiovascular side effects. These side effects include stroke, myocardial infarction (heart attack), systemic embolism and death.

The FDA is updating the safety labels after the most recent study, called PALLAS (Permanent Atrial FibriLLAtion Outcome Study Using Dronedarone on Top of Standard Therapy) had to be halted prematurely, because the researchers found that Multaq significantly increased a user’s risk of suffering a cardiovascular event. The study was conducted by the manufacturer of Multaq, Sanofi-Aventis.

The changes to the safety information includes the following recommendations:

• Multaq should not be prescribed to people with permanent atrial fibrillation
• People who are taking Multaq must have their cardiac rhythm monitored every three months via electrocardiocram (ECG). If the person has permanent atrial fibrillation, Multaq should be stopped.
• Multaq only reduces hospitalization rates in people with non-permanent atrial fibrillation
• Patients given Multaq should also be given medication to reduce the risk of blood clots

Although Multaq will not be approved for people with permanent atrial fibrillation, it is approved for atrial flutter, and “paroxysmal” or persistent atrial fibrillation. The safety of Multaq for these heart problems was established in the ATHENA study in 2009, which based its conclusions on a reduced number of hospitalizations. The FDA has not changed its approval of Multaq for people with non-permanent atrial fibrillation, and still believes that the benefit of reduced hospitalizations outweighs the potential risk of serious cardiovascular events.

This recent safety warning is the most recent FDA Multaq warning. The previous warning was in January of 2011, after the FDA received two reports of people who had suffered acute liver failure after taking Multaq. These patients required an immediate liver transplant. The FDA updated the information to recommend that during the first six months that a patient is using Multaq, he or she should undergo regular liver enzyme tests.

What is atrial fibrillation? It is a heart problem that occurs when the upper two chambers of the heart do not beat in rhythm with the lower two chambers. The result is a “flutter,” irregular heartbeat, or racing heart-rate. It can be life-threatening if blood begins to pool in the upper chambers, where it can form blood clots. If these blood clots are pumped to the brain or other major internal organs, they can cause stroke, pulmonary embolism, heart attack, and death. A person with atrial fibrillation may also suffer a weakened heart, which can lead to heart failure, and death.