Atrial fibrillation (also know 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, approximately 2.7 million Americans are living with Afib.
Atrial fibrillation has long been treated with the blood thinner Coumadin, also known as warfarin, which was approved by the FDA in 1954. However, new blood thinners, or anticoagulants, to treat Afib have come on the market in the last six years, including one known as Pradaxa.
According to University of Michigan Frankel Cardiovascular Center cardiologist Dr. Geoffrey Barnes, “Many patients wonder: Does newer mean better?” Not always, he says. “Choosing between medications such as warfarin or Pradaxa 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 Dr. Barnes, “there are advantages and disadvantages to each.”
According to Dr. Barnes, “Pradaxa is the first real alternative to warfarin.”
Approved by the FDA in 2010 to prevent stroke and systemic blood clots in patients with atrial fibrillation, and for the treatment and prevention of deep venous thrombosis and pulmonary embolism, many Afib patients are choosing Pradaxa over warfarin.
Dr. Barnes explains the pros and cons of both.
Pradaxa vs. warfarin
Dosage and monitoring
- Warfarin: The right dose of warfarin varies from patient to patient and can depend on diet, age and other medications being taken. 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 on a regular basis. However, says Dr. Barnes, “Warfarin stays in your system longer than Pradaxa, 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.”
- Pradaxa: “This anticoagulant does not require frequent blood tests, but a periodic check of your kidney function is important, says Dr. Barnes. “Pradaxa works quickly but also leaves the system quickly, so if a patient forgets to take it, there could be serious complications.”
Interactions with food and other meds
- Warfarin: Warfarin 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 the effectiveness of warfarin. “Quickly cutting back on Vitamin K can put patients at risk for bleeding complications,” says Dr. Barnes.
- Pradaxa: This anticoagulant isn’t subject to the same concerns as warfarin in terms of interacting with other medications or foods because it is not cleared by the liver. Instead, says Dr. Barnes, “It is cleared by the kidneys, which can lead to complications for patients with kidney issues.” Patients with Afib are susceptible to kidney issues, he adds.
Reversing the drugs’ effects
- Warfarin: Warfarin is considered completely reversible: A patient can get an infusion of anti-clotting factors to reverse the effects of warfarin, although the effects are not immediate.
- Pradaxa: A new reversal agent for Pradaxa (Praxbind) was recently approved by the FDA, making the drug immediately reversible.
Patients deciding which medication to choose often are influenced by cost (Pradaxa is significantly more expensive than warfarin) along with the fact that Pradaxa does not require regular blood tests, says Dr. Barnes. However, these patients need to be vigilant about taking their medication.
“At U-M, we believe all patients on anticoagulants should be monitored, not just those on warfarin,” Dr. 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.”
Take the next step:
- Be sure to talk to your doctor about which medication is right for you.
- Read about the advantages of warfarin alternatives.
- Learn the 5 important warfarin precautions.
The University of Michigan Samuel and Jean Frankel Cardiovascular Center is a top-ranked heart and heart surgery program among Michigan hospitals. To learn more, visit our website at umcvc.org.