If you are reading this article, chances are that you or someone you know takes warfarin or one of the other anticoagulants to hit the market in the last few years. One of the big questions everyone has these days is “what is the best choice?” This is even more the case with the recent news of Pradaxa’s $650 million dollar payout to settle more than 4000 personal injury and product liability lawsuits. So how does one decide?
Lets take a momet to review of some of major points…
- The gold standard: Warfarin (Coumadin) (Pradaxa), Rivaroxaban (Xarelto), Apixaban (Eliquis)
- Has been around since the 1940s.
- Dosing is individualized and can change over time.
- Routine blood tests are required to insure the proper dose is taken.
- There are dietary guidelines that need to be followed.
- Interactions with many other medicines exist.
- Bleeding is the most common complication.
- There is an antidote.
- The other oral anticoagulants: Dabigatran
- FDA approved since 2010 (Pradaxa), 2011(Xarelto) and 2012 (Eliquis).
- Dosing is standardized.
- No monitoring is required.
- No food restrictions.
- A few significant drug interactions exist.
- Bleeding is the most common complication.
- There are currently no antidotes for any of these medications.
Now Lets Compare:
1. New doesn’t always mean better. We learn more about a medicine’s side effects and benefits over time as more people of different ages and with various medical problems take it. Warfarin has been used in humans for over half a century. We know what it does –both good and bad. With the other agents, we have yet to discover the long-term risks and benefits.
2. “One dose fits all” may sound appealing—this is how the new medicines were marketed as having an advantage over warfarin. However, it is becoming clearer that this is not the case and that dose adjustments may be necessary for some patients.
3. Regular blood tests, to some, may appear to be a burden. But as those who test at home each week know, it takes very little time, is easy to do and is quite reassuring to know that the medicine is working properly and providing the best possible protection from stroke and blood clots. Additionally, it is coming to light that testing the blood levels of the newer anticoagulants may be an important step that was initially overlooked.
4. Understanding the influence of dietary Vitamin K is a big part of taking warfarin, but for most, a stable diet becomes second nature and doesn’t dramatically impact one’s lifestyle in the long run.
5. While there are many drug interactions between warfarin and other medicines, they are predictable: we know what they are and how to deal with them. The newer agents pose a trickier problem as the drug interactions that exist are not well defined and are often overlooked by practitioners who aren’t knowledgeable about these anticoagulants.
6. Bleeding is the most common complication of ALL anticoagulants—old and new. These medicines slow down and impair the clotting process and so bleeding is a possibility with any of them.
7. An antidote—isn’t it nice to know that if your INR gets too high or if you are bleeding that there is something you can take to REVERSE the effects of warfarin quickly? Not the case with other anticoagulants. You just have to wait it out. Yikes.
8. Even with the expense of blood tests and INR management factored in, warfarin still costs less than any of the alternatives.
Warfarin remains a great choice for anticoagulation. Is there a place for the other agents? Of course—it is probably a great option for many people. I also believe that as they continue to do research and improve upon the medicines that have already been released, there will be better—and safer—alternatives in the future. But today, with what is currently available, one must be very cautious when choosing an anticoagulant. A patient’s age, weight, kidney function and other medicines need to be considered. These newer anticoagulants are not medicines that should be prescribed to patients and forgotten about until the next yearly exam.
In head-to-head trials with warfarin, Pradaxa, Xarelto and Eliquis looked good—in some cases better than warfarin. But clinical trials don’t always represent the diversity of people who ultimately take the medication. Additionally, in the trials, warfarin wasn’t always managed well. Sub-analyses demonstrated little difference between the other oral anticoagulants and warfarin when the INR was under good control—as it generally is with people that test their INRs at home.
Warfarin may not always be well-liked, but it is well-understood and there is A LOT to be said for knowing what you are getting into. Top it off with convenient, weekly at-home INR testing… it’s the decision I’d make. No question about it.