The blood thinner Pradaxa (abigatran) was quickly adopted after its approval into clinical practice for stroke prevention in patients with atrial fibrillation, but a team of researchers say that it has had little impact on its target population.
Lead author Dr. G. Caleb Alexander, a research scientist in the Johns Hopkins Bloomberg School of Public Health, and colleagues used data from the IMS National Disease and Therapeutic Index to quantify patterns of oral anticoagulant – both Pradaxa and long-used warfarin – use among study participants from 2007 until 2011. They found that despite rapid adoption of Pradaxa for its approved indication, a large proportion of atrial fibrillation patients – 2 in 5 – did not receive treatment with blood thinners.
Additionally, researchers found that the majority of patients who were prescribed Pradaxa were not taking it as a treatment for atrial fibrillation – which is its only approved use in the United States – but for off-label indications such as venous thromboembolism, or blood clots.
Doctors have the discretion to prescribe drugs for indications other than those that have been approved by the FDA, however drug companies are forbidden to market drugs for unapproved or off-label uses.
Pradaxa was cleared by the FDA in 2010, making it the first blood thinner since warfarin more than 50 years ago to be approved to prevent strokes in patients with atrial fibrillation. Within 14 months of Pradaxa’s approval, the FDA received thousands of adverse event reports involving the drug, including 900 cases of gastrointestinal bleeds and 500 cases of death from bleeds.