Are new blood thinners better than Coumadin?

Blood thinners are a class of medications, also known as anticoagulants, that have one main purpose: to keep your blood flowing smoothly through your veins and arteries. They do so by preventing blood clots from forming initially, and keeping existing blood clots from getting any bigger. Blood clots are dangerous because they can move through your bloodstream, lodge somewhere—like your heart, lungs, or brain—and prevent essential blood flow. Blood thinners are part of the treatment plan for many cardiovascular conditions, from atrial fibrillation, or irregular heart rhythm, to deep vein thrombosis. 

Historically, there was one main oral blood thinner—Coumadin (warfarin)—that could prevent these life-threatening issues. But, it came with some drawbacks. If you’ve watched any TV lately, you’ve likely seen advertisements for the new blood thinners that were created to fix those issues, like Xarelto and Eliquis. Read on to learn everything you need to know about these alternatives to Coumadin.

The problem with Coumadin

Coumadin (warfarin) is one of the oldest cardiac medications, first popularized when President Dwight D. Eisenhower had a heart attack while in office. It’s very effective at preventing clots by inhibiting vitamin K, a vitamin your body uses to create the proteins it needs to clot your blood. The drawback is that changes in certain diet and eating habits—like consuming varying amounts of foods rich in vitamin K (rather than eating a consistent amount) or drinking alcoholic beverages, can affect the blood’s ability to clot. Excess vitamin K can make the blood more likely to clot. This is why healthcare providers recommend patients who take warfarin eat a consistent amount of foods rich in vitamin K. On the other hand, alcohol can thin the blood. People taking Coumadin need frequent blood tests to check their status and constant dose adjustments to achieve the perfect balance between bleeding too much or forming clots. 

What are new blood thinners?

Between 2010-2015 a series of new blood thinners hit the market, each deemed either more or equally effective compared to warfarin for clot prevention by the U.S. Food and Drug Administration (FDA).  

1. Pradaxa (dabigatran), initial approval 2010
2. Xarelto (rivaroxaban), initial approval 2011
3. Eliquis (apixaban), initial approval 2012
4. Savaysa (edoxaban), initial approval 2015

These drugs were initially referred to as novel oral anticoagulants (NOACs). Now that they have been around for over five years, the preferred term is direct-acting oral anticoagulants (DOACs). “With the first, Pradaxa, out since 2010, they’re not so novel anymore,” explains Frank Dorsa, MD, a cardiologist with the NewYork-Presbyterian Medical Group Hudson Valley in New York. Savaysa, the last to be approved, has never captured as large a market share as Eliquis or Xarelto as it did not offer any significant advantage over the other three DOACs.

How do new blood thinners work?

Blood thinners don’t actually make the blood thin, explains Raman Mitra, MD, a cardiologist and director of the electrophysiology laboratory at North Shore University Hospital in New York. There are a dozen or so proteins in the blood that collaborate in clotting, and if any one of those elements is impeded, blood takes longer to clot, and therefore the chance of a stroke is lessened. Instead of inhibiting vitamin K, each of the new blood thinners interferes with a key step in clot formation. 

The result is a more reliable clotting effect. Meaning, the dosage doesn’t need to be constantly tinkered with, and your diet doesn’t affect how well it works. It’s less of an impediment to a person’s life.

What makes new blood thinners better than Coumadin?

Warfarin has two clear strengths the DOACs don’t have. First, it is the only option for those with a mechanical heart valve, says Dr. Mitra. Also, warfarin is by far the least expensive. However, warfarin alternatives are a better choice in almost every other way. According to Dr. Mitra and Dr. Dorsa, new blood thinners: 

• Are superior in preventing strokes and death.
• Are associated with less internal bleeding, particularly in the head. 
• Have standard dosing, providing protection within a few hours of the first dose. Warfarin’s dosing may take up to a week to fine tune.
• Have no food restrictions, while warfarin’s effectiveness depends on eating a consistent amount of vitamin K, found in leafy green vegetables.
• Do not require testing unlike warfarin, which requires frequent testing.
• Have fewer drug interactions, while warfarin’s efficacy may be affected by common antibiotics among other drugs.

What are the drawbacks to new blood thinners?

While the newer blood thinners are most often the best choice, they do have some side effects and special considerations, just like any Rx. They include the following.

• Cost: The new blood thinners are much more expensive than Coumadin. “I tell patients to find out which drug is covered best in their insurance plan, and we’ll use that one,” Dr. Mitra explains.
• Dosage: Xarelto and Savaysa are taken once a day, while Eliquis and Pradaxa are taken twice a day. Dr. Mitra says with patients who may not always remember the additional dose, he is more likely to prescribe Xarelto or Savaysa. 
• GI bleeding: Xarelto, Savaysa, and Pradaxa have all been associated with gastrointestinal (GI) bleeding, even comparing unfavorably with Warfarin. “So if someone is at risk for GI bleeding—if they report heartburn or maybe they had a bleeding ulcer 10 years ago—I’m a little bit more likely to prescribe Eliquis,” Dr. Dorsa says. 
• Kidney function: “If someone has kidney disease, we’re not likely to use Pradaxa because that drug is completely excreted by the kidneys,” Dr. Mitra explains. “For someone with kidney disease, we’re more likely to prescribe Eliquis, Xarelto, or Savaysa.” 
• Reversal of blood thinner effects: Blood thinners “push the needle a little bit more toward fluidity and bleeding as opposed to clotting,” Dr. Mitra says. “In the case of an injury—say you cut yourself or bump yourself—your blood will clot but it will just take a little longer, maybe three to five minutes.” In a bleeding emergency, warfarin can be reversed in four to six hours with frozen plasma. With the DOACs, Eliquis and Xarelto will begin to reverse after cessation of the drug, within 24 to 48 hours. Reversal agents are available for all of the new blood thinners, says Dr. Mitra, but tend to be very expensive.

Which is the best new blood thinner?

The new blood thinners are comparable, but is there one that is best? Since there has been no study comparing the four new blood thinners to one another, there’s no clear answer. Ultimately, finding the best medication should be what you and your healthcare provider decide upon. Your provider will look at your medical history and help you decide which drug you’re best-suited for.

Often, the best approach is to try the medication that insurance will cover and has the lowest risk of side effects. If the treatment you’re on isn’t working for you, confer with your physician. With time and perseverance, you’ll find the medication that’s best for you.