Regulators with the Food and Drug Administration have warned that Multaq, a cardiac drug Sanofi, has been linked with fatal heart problems in a clinical trial the company recently ended.
Multaq is prescribed to control atrial fibrillation, the most common type of irregular heartbeat which is found in about 2.2 million Americans. It is a condition in which the primary electrical impulse that causes the atria - the two upper chambers of the heart - to contract instead fires erratically, causing several other nodes, or electrical impulse points, to fire instead.
The resulting erratic firing causes the atria to become inefficient, and heart rates can climb to about 150. The condition can lead to heart attacks or, more commonly, stroke, because blood does not flow through them as quickly, causing clots.