A new study has found that Coumadin (generic: warfarin) is highly effective at preventing strokes and not as risky as Pradaxa, Boehringer Ingelheim’s controversial new blood-thinning medication. Researchers found that not only were stroke rates extremely low among Coumadin users, but that the numbers seem to be improving over time. In recent months, Pradaxa (generic: dabigatran) has been increasingly linked to serious internal bleeding events, hemorrhaging, rectal bleeding, and strokes.
What’s the problem?
Research published in the March 26, 2012 online edition of the Archives of Internal Medicine analyzed the effectiveness of stroke prevention among individuals treated with warfarin who suffered from nonvalvular atrial fibrillation, the same condition that Pradaxa was approved to treat.
The results of the study indicated that stroke rates were exceedingly low among warfarin users, and that the overall numbers were improving with time. The new research seems to imply that warfarin will likely continue to be the first-line blood thinning drug for the foreseeable future, despite competition from Pradaxa, which was initially marketed as a superior alternative to Coumadin/warfarin.
Since it was first approved by the U.S. Food & Drug Administration (FDA) in October 2010, Pradaxa has been widely prescribed amid aggressive marketing by Boehringer Ingelheim. However, the drug has become increasingly associated with serious internal bleeding events, which have caused hundreds of reports of death and serious hemorrhages in the short time it has been on the market.
Pradaxa is the first in a new class of anticoagulants known as ‘direct thrombin inhibitors’ that are designed to work by inhibiting an enzyme that causes blood to clot. Direct thrombin inhibitors are marketed as superior alternatives to Coumadin/warfarin because they are supposed to require less monitoring. However, warfarin internal bleeding events can be counteracted with vitamin K, while Pradaxa and other drugs from the same class do not have the same quick fix.
In the new study, researchers gathered information from a number of databases on patients being treated with warfarin, and found that the annual rate of incidence for stroke or systemic embolism was an insignificant 1.66%. Additionally, the study found that major internal bleeding events occurred in 1.4 to 3.4% of patients being treated with warfarin per year. When taken as a whole, these statistics indicate that negative side effects have been declining over the years, and that the use of warfarin has been increasing in effectiveness.
Over the past several months, an increasing number of Pradaxa lawsuits have been filed in courthouses around the country. These complaints allege that Boehringer failed to provide adequate warnings about the risk of internal bleeding and the lack of reversal agent associated with Pradaxa. If the FDA requires strengthened Pradaxa warning labels in the coming months, it could prove yet another setback for the newer, more expensive blood-thinning medication.
According to a January 2012 report released by the Institute for Safe Medication Practices, more hemorrhaging events linked to Pradaxa were reported to the FDA during the first quarter of 2011 than were reported with any other drug monitored by the group. During that time period, at least 505 Pradaxa bleeding events were reported, compared to just 176 cases reported in connection with Coumadin, which came in second on the list.