Study: Pradaxa May Increase Viral Infection Risks, SeverityApr 3, 2013
An emerging study reveals that the blood thinner Pradaxa (dabigatran etexilate mesylate) may increase the risks for, and severity of, viral infections.
In recent months, Pradaxa also has been linked to injuries and deaths related to uncontrollable bleeding.
University of North Carolina researchers found that Pradaxa blocks a key component in the human blood clotting system, which may increase these viral infection risks. This includes increased risks for the flu and myocarditis, a cardiac viral infection that is a significant cause of sudden death in children and young adults, said News-Medical.
For some 50 years, patients diagnosed with atrial fibrillation, an irregularity of the heartbeat, and others who are at risk of forming life-altering blood clots, have been prescribed warfarin, an anticoagulant medication, explained News-Medical. The U.S. Food and Drug Administration (FDA) recently approved Pradaxa for atrial fibrillation patients.
Pradaxa is a blood-thinning medication used to reduce the risk of stroke and blood clots in patients with non-valvular atrial fibrillation (AF), a common heart rhythm abnormality. The drug, however, is not approved for patients with atrial fibrillation caused by heart valve problems. Pradaxa also inhibits thrombin, which is the central coagulation activator in the body’s blood clotting system, explained News-Medical.
When thrombin activity is blocked, normal coagulation activities are interrupted. And, although clot formation is reduced, the study suggests that immune responses are also reduced. "Our findings show that blocking thrombin reduces the innate immune response to viral infection," said the study’s senior author, Nigel Mackman, PhD, the John C. Parker Distinguished Professor of Medicine in the division of hematology and director of the UNC McAllister Heart Institute, according to News-Medical. "The use of the new generation of blood thinners might increase the risk and severity of flu and myocarditis," Mackman added.
Mackman also pointed out that "We are now determining if the traditional long-term anticoagulant warfarin has the same effect on viral infection or is this specific to the new blood thinner," News-Medical said. A report on the research appears in the March 2013 issue of The Journal of Clinical Investigation.
Another recent study revealed that Pradaxa should not be used for the prevention of stroke or blood clots in patients who have been implanted with mechanical heart valves. The FDA advised health care professionals and the public of the dangers of Pradaxa for patients implanted with these devices.
In fact, a clinical trial in Europe was ceased when Pradaxa users were seen to be likelier to experience strokes, heart attacks, and blood clots forming on the heart devices when compared to patients taking warfarin. The study also found that patients taking Pradaxa experienced more bleeding after valve surgery than those taking warfarin.
The use of Pradaxa in patients with valve replacements made of natural biological tissue has not been evaluated.