The new blood thinner medication Pradaxa may not be as safe as warfarin, the industry standard that has been trusted for years.

Warfarin, also sold under the brand name Coumadin, has been in use for decades and is often the preferred blood thinner to manage clotting disorders and pulmonary emboli. The drug manages blood clots by influencing vitamin K. This vitamin is necessary for normal blood clotting, and reducing the amount of vitamin K in the blood can reduce the clotting.

The mechanism behind warfarin makes it finicky, but also predictable. If a patient comes into the emergency room with severe bleeding due to warfarin, the condition can be managed by flushing the body with vitamin K to restore the clotting ability.

Although warfarin is effective and trusted, it does have its negatives. Regular blood tests are required with warfarin treatment to measure clotting time and efficacy of the drug. These tests allow doctors to determine if dosages need to be adjusted to preserve the balance of clotting and bleeding.

As mentioned earlier, the body can be flushed with vitamin K to manage excessive bleeding due to warfarin, but patients have to avoid foods high in vitamin K so that they do not counteract the medication or be consistent in their diet so that the effects of certain foods doesn’t vary. Foods to avoid include grapefruit, cranberry, spinach, broccoli, brussels sprouts and more.

Warfarin also has a large number of medications that need to be avoided due to potentially life threatening interactions.

When the new blood thinner medication Pradaxa was released, it was directly competing with warfarin. To get the marketing edge, the drug was marketed with the catch-phase “the Pradaxa difference.” Advertisements reportedly stated that Pradaxa is better than warfarin because there are no regular blood tests or dietary restrictions associated with the drug.

However, the drug may be associated with severe bleeding events. Within the first three months on the market, the U.S. Food and Drug Administration (FDA) received 307 reports involving internal bleeding in connection with the new blood thinner medication Pradaxa.

Within the first year, there were reportedly 260 deaths in Pradaxa patients due to internal bleeding, gastrointestinal bleeding, hemorrhage and stroke.

Pradaxa was the first modern blood thinner to have a reversal agent approved. Although this relatively new treatment will mean that future bleeding events may be manageable, some claim that the drug should have had a working antidote when it was released rather than years later.

Deciding which blood thinner to chose is a tough decision. Both warfarin and Pradaxa are effective blood thinners and each have their own disadvantages. However, if warfarin is working for patients, Dr. Richard Kovacs, clinical director of Krannert Institute of Cardiology at Indiana University, says there is no reason to switch and risk developing new complications.

“If you’ve been on warfarin, you’re stable, don’t have bleeding problems, and don’t mind going to the laboratory,” Kovacs said to WebMD, “In my opinion, there’s generally not a compelling reason to switch.”