In its ongoing review of the blood thinner Pradaxa (dabigatran), the FDA recently completed a new study in Medicare patients comparing Pradaxa to the blood thinner warfarin (Coumadin, Jantoven, and generics), for risk of ischemic or clot-related stroke, bleeding in the brain, major gastrointestinal (GI) bleeding, myocardial infarction (MI), and death. Pradaxa and warfarin are used to reduce the risk of stroke and blood clots in patients with a common type of abnormal heart rhythm called non-valvular atrial fibrillation (AF).
Bleeding that may lead to serious or even fatal outcomes is a well-recognized complication of all anticoagulant therapies. In a large clinical trial with 18,000 patients that compared the efficacy and safety of Pradaxa and warfarin (RE-LY, 2010), the rate of serious bleeding was similar between the two drugs. However, after Pradaxa’s approval, a large number of reports of bleeding were submitted to the FDA’s Adverse Events Reporting System (AERS) database.
The new study included information from more than 134,000 Medicare patients, 65 years or older, and found that among new users of blood-thinning drugs, Pradaxa was associated with a lower risk of clot-related strokes, bleeding in the brain, and death, than warfarin. The study also found an increased risk of major gastrointestinal bleeding with use of Pradaxa as compared to warfarin. The risk of myocardial infarction was similar for the two drugs.
Importantly, the new study is based on a much larger and older patient population than those used in the FDA’s earlier review of post-market data, and employed a more sophisticated analytical method to capture and analyze the events of concern. This study’s findings, except with regard to myocardial infarction, are consistent with the clinical trial results that provided the basis for Pradaxa’s approval.
As a result of the FDA’s latest findings, it still considers Pradaxa to have a favorable benefit to risk profile and has made no changes to the current label or recommendations for use. Patients should not stop taking Pradaxa (or warfarin) without first talking with their health care professionals. Stopping the use of blood-thinning medications such as Pradaxa and warfarin can increase the risk of stroke and lead to permanent disability and death. Health care professionals who prescribe Pradaxa should continue to follow the dosing recommendations in the drug label.
See the FDA Safety Announcement
See also Medical Law Perspectives, December 2013 Report: Thicker Than Water: Liability When Blood Clots Cause Injury or Death
See also Medical Law Perspectives, May 2013 Report: Drugs, Dosage, and Damage: Physician Liability for Prescribing or Administering Medication
See also Medical Law Perspectives, October 2013 Report: Brain Aneurysm and Subarachnoid Hemorrhage: Failure to Diagnose, Delayed Diagnosis, Misdiagnosis
See also Medical Law Perspectives, November 2013 Report: Diagnosis and Treatment of Heart Attacks: Liability Issues