Atrial fibrillation, also known as Afib, is a quivering or irregular heartbeat (arrhythmia) that can lead to blood clots, stroke, heart failure and other heart-related complications. According to the American Heart Association, at least 2.7 million Americans are living with Afib.

Afib has long been treated with the blood thinner Coumadin, also known as warfarin, which the FDA approved in 1954. However, newer blood thinners, or anticoagulants, to treat Afib have been introduced in the last decade, including Xarelto (rivaroxaban) and Eliquis (apixaban).

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According to University of Michigan Frankel Cardiovascular Center cardiologist Geoffrey Barnes, M.D., M.Sc., many patients wonder: Does newer mean better? Not always, he says. "Choosing between medications such as Coumadin, Xarelto or Eliquis depends on the individual patient's needs and preferences."

All blood-thinning medicines slow the formation of blood clots, preventing complications such as valve obstruction and blood clots that travel to the brain and cause stroke.

But, says Barnes, "there are advantages and disadvantages to each."

The FDA approved Xarelto and Eliquis nearly 10 years ago to prevent stroke and systemic blood clots in patients with Afib and for the treatment and prevention of deep vein thrombosis and pulmonary embolism. Many Afib patients are now choosing Xarelto or Eliquis over Coumadin.

Barnes explains the pros and cons of these medications.

Coumadin vs. Xarelto/Eliquis

Dosage and monitoring

Coumadin: The right dose of Coumadin varies by patient and can depend on diet, age and other medications a patient takes. The dosing is a delicate balance: Too much can increase bleeding, and too little might not reduce the risk of stroke. For this reason, blood levels need to be checked regularly.

However, Barnes says, "Coumadin stays in your system longer than Xarelto or Eliquis, so if you miss a day or two, it isn't a big problem, although a patient's blood levels still need to be tested on a daily basis."

Xarelto/Eliquis: "These anticoagulants do not require frequent blood tests, but a periodic check of your kidney function is important," Barnes says. "Xarelto and Eliquis work quickly but also leave the system quickly, so if a patient forgets to take their daily medication, there could be serious complications."

While Xarelto is taken once a day, Eliquis is taken twice a day, increasing the risk of patients missing their second dose.

Interactions with food and other meds

Coumadin: Coumadin is highly susceptible to interactions with food and other medications. The drug requires patients to have regular blood tests and to watch their intake of vitamin K, which is found in foods such as spinach, kale and chard.

Too much vitamin K in the blood can lessen Coumadin's effectiveness. "Quickly cutting back on vitamin K can put patients at risk for bleeding complications," Barnes says.

Xarelto/Eliquis: These anticoagulants aren't subject to the same concerns about food and medication interactions as Coumadin is, because they are not cleared by the liver.

"Instead, they are cleared by the kidneys, which can lead to complications for patients with kidney issues," Barnes says. "Patients with Afib are susceptible to kidney issues."

Reversing the drugs' effects

Coumadin: Coumadin is considered completely reversible in the case of life-threatening or uncontrolled bleeding. A patient can get an infusion of anti-clotting factors to reverse the effects of Coumadin, although the effects are not immediate.

Xarelto/Eliquis: A new reversal agent known as Andexxa, recently approved by the FDA, immediately reverses the effects of these blood thinners. However, Andexxa is not readily available at all hospitals, Barnes says.

There may also be a reduced need to reverse the effects of Xarelto and Eliquis, as these medications are less likely than Coumadin to cause severe bleeding (e.g., bleeding in the brain).

Cost considerations

Coumadin: Cost often influences patients deciding on a medication. While Coumadin is considerably less expensive than the newer brands, it requires regular blood tests, which are a cost consideration.

Xarelto/Eliquis: These new medications do not require routine lab monitoring as with Coumadin, but they are significantly more expensive and patients may pay higher medication copays, depending on insurance coverage.

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"At U-M, we believe all patients on anticoagulants should be monitored, not just those on Coumadin," Barnes says. For this reason, U-M offers its monitoring service to all patients on anticoagulants.

"Patients benefit when they have a knowledgeable anticoagulation provider, such as a pharmacist or nurse, to contact with questions and to ensure they are not having difficulty taking their anticoagulant regularly," he says.

While the newer medications provide doctors with more options for Afib patients in the prevention of stroke, Barnes advises interested patients to speak with a health care professional to find out which medication is best for them.