New Blood Thinner Review Delayed Amid Concerns Over Pradaxa Safety

Fears over bleeding problems with Pradaxa may have contributed to the FDA’s recent decision to delay their review of Eliquis, a proposed blood thinner that is part of the same new generation of medications. 

Pfizer and Bristol-Myers Squibb, the companies developing Eliquis, announced last month that the FDA was delaying a decision on the new drug at least three months. The drug makers indicated that they were asked to submit additional information about the clinical trials, which will take additional time for the FDA to review.

The request for additional information by the FDA coincides with its investigation into Boehringer Ingelheim’s Pradaxa, which was the first in a class of new blood thinners known as “direct thrombin inhibitors”, which inhibit the enzyme in the blood that causes blood to clot.

Johnson & Johnson’s Xarelto (rivaroxaban), which was introduced in November 2011 despite FDA staff recommendations against the drug, is the only other medication within the same class that is approved in the United States. If approved, Eliquis would be the third.

The blood thinners were supposed to be superior to older anticoagulant drugs, like Coumadin (warfarin), as they require less monitoring.

Within months of Pradaxa’s introduction in October 2010, the medication became widely used because it was marketed as easier to use for prevention of stroke among patients with atrial fibrillation. However, when serious bleeding events do occur with Pradaxa, they can not be quickly counteracted by doses of Vitamin K like with Coumadin, which some experts suspect may be the cause for the high number of Pradaxa deaths and serious bleeds that have been reported during the short period of time the medication has been available.

According to a report released by the Institute for Safe Medication Practices in January 2012, more instances of hemorrhage with Pradaxa were reported to the FDA’s Adverse Event Reporting System during the first quarter of 2011 than were reported in association with any other drug monitored by the group.  At least 505 instances involving Pradaxa bleeding problems were reported, compared to 176 cases reported with warfarin/Coumadin, which was second on the list.

Some scientists have raised questions about the clinical trials involving Pradaxa, and the FDA, Canadian and European health agencies have all opened investigations into the drug’s safety due to the large number of serious bleeding events.

A number of individuals throughout the United States are now pursuing a Pradaxa lawsuit against the Boehringer Ingelheim, alleging that the drug maker failed to properly research their medication or warn about the serious bleeding risks associated with side effects of Pradaxa due to the lack of a reversal agent.