Pradaxa Stomach Bleed Risks Higher Than Warfarin: FDA

Following months of studies, conflicting data and mounting reports of bleeding problems, federal drug regulators issued an updated statement on the potential side effects of Pradaxa, suggesting that users of the anticoagulant may face an increased risk of stomach bleeds compared to warfari.  

In a drug safety communication issued on May 13, the FDA indicated that while Pradaxa was associated with a lower risk of clot-related strokes, brain bleeds and death, there was an increased risk of major gastrointestinal bleeding when compared to the decades-old competitor it was designed to replace.

The new data comes from a recently-completed study that involved information on more than 134,000 Medicare patients, age 65 or older. The FDA study found that using Pradaxa increased the risk of gastrointestinal (GI) bleeding by 28%, with 34.2 GI bleeding incidents for every 1,000 person-years of use. That compares to only 26.5 incidents for users of warfarin.

The study also found that Pradaxa carried only 80% of the risk of stroke when compared to warfarin, and only had about a third of the risk of brain bleeding. The risk of heart attacks was about the same for both drugs, and the mortality rate for Pradaxa patients was slightly lower.

Despite concerns about the risk of bleeds on Pradaxa, the FDA indicates that the benefits provided by the drug still appear to outweigh the risks, and determined that no label changes will be made. The determination comes about a month after the agency expanded the approved uses of Pradaxa to include prevention of deep vein thrombosis and pulmonary embolism.

Pradaxa Bleeding Concerns

Pradadxa (dabigatran) was first approved by the FDA in October 2010, for prevention of strokes among patients with atrial fibrillation. It was the first member of a new class of medications that have been promoted as superior alternatives to warfarin, also known by the brand name Coumadin, since they require less monitoring during treatment. However, shortly after its introduction, Pradaxa began to rack up a record number of adverse event reports after patients experienced uncontrolled bleeding events.

There have been thousands of reports of injuries and hundreds of deaths associated with Pradaxa use since it was introduced by Boehringer Ingelheim. Many doctors have expressed concerns about the lack of an effective reversal agent for Pradaxa. While doctors are able to reverse the blood thinning effects of warfarin with a dose of vitamin K, there is no such antidote available for Pradaxa users.

Boehringer Ingelheim currently faces more than 2,000 Pradaxa lawsuits filed on behalf of individuals throughout the United States who allege that the drug maker failed to adequately warn about the risks associated with the anticoagulant and the lack of an effective reversal agent. It is unclear what impact the FDA’s decision not to require additional warnings will have on the litigation.

All federal complaints are currently centralized before U.S. District Judge David R. Herndon in the Southern District of Illinois for coordinated handling as part of an MDL, or multidistrict litigation. The first Pradaxa trials are expected to begin later this year, with a series of four “bellwether” cases set to go before juries between September 2014 and March 2015.