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Whether you have atrial fibrillation (Afib) or a history of developing blood clots in your legs or lungs, you need to talk to your doctor about taking an oral anticoagulant medication. In a person with Afib, these blood thinners can prevent a blood clot from forming in the heart, traveling to the brain and causing a stroke. They also can ward off development of blood clots in the veins of the legs (deep vein thrombosis) that can move to the lungs and cause a life-threatening pulmonary embolism.
You have a choice between the old standby, warfarin (Coumadin®), or newer blood thinners known as direct oral anticoagulants (DOACs). Each drug has advantages and disadvantages that you should carefully discuss with your physician. You and your doctor will need to consider what caused your blood clot, your history of bleeding problems, all other medications you’re taking, your insurance coverage, the properties of each blood-thinning medication, and your own personal preferences.
Differences Between the Blood Thinners
Warfarin works by inhibiting vitamin K, which your body needs to form clots. Consequently, changes in dietary intake of vitamin K (found in green leafy vegetables, broccoli, cauliflower, and other foods) can affect the activity of warfarin. Moreover, a wide array of medications and supplements can interact with warfarin and alter its effects.
Patients taking warfarin must undergo periodic calculations of their international normalized ratio (INR), a measure of how quickly your blood clots. If the INR is too high, your risk of bleeding increases; if it’s too low, you face a greater risk of blood clots. Some patients on warfarin require frequent dose adjustments to keep their INR in a healthy, therapeutic range.
WHAT YOU CAN DO
● Before starting therapy with any of the blood thinners, tell your doctor about all supplements or medications you take that inhibit blood clotting, such as aspirin, nonsteroidal anti-inflammatory drugs (e.g., Advil®, Motrin® and Aleve®), clopidogrel (Plavix®), prasugrel (Effient®), ticagrelor (Brilinta®) or any medication containing heparin.
● Check with your insurance provider to see which, if any, of the direct oral anticoagulants (DOACs) it covers. Talk to your doctor and pharmacist about available discounts and drug-assistance programs.
● While on anticoagulation therapy, avoid contact sports or other activities that increase your risk of a potentially life-threatening bleeding event.
● Carry a card in your wallet, or wear a bracelet or pendant, identifying which anticoagulant drug you take.
The newer blood thinners—apixaban (Eliquis®), dabigatran (Pradaxa®), edoxaban (Savaysa®), and rivaroxaban (Xarelto®)—are given in fixed doses, do not require INR monitoring, have few medication interactions, do not require dietary restrictions, and carry a lower risk of bleeding than warfarin.
Plus, compared with warfarin, it’s less complicated to stop DOAC therapy before surgery or other invasive medical procedures and to resume it afterward. Because of the convenience and patient preference, more and more physicians are prescribing the newer blood thinners than warfarin for patients who are suitable candidates for them.
Drawbacks of DOACs
Despite their advantages, the DOACs do have some downsides—namely, their higher price. Available as a generic, warfarin costs about $4 to $14 for a 30-day supply, whereas the newer blood thinners range in price from upwards of $300 to more than $400 for a 30-day supply. However, the expense of traveling to an anticoagulation clinic and any fees you might incur for INR monitoring with warfarin might negate the cost savings of the older drug somewhat.
Additionally, questions remain about using DOACs in cancer patients, and overall, warfarin remains the preferred choice for patients with liver disease, kidney failure, mechanical heart valves, and certain clotting disorders known as thrombophilia.
And, while warfarin’s effects can be reversed quickly in the event of excessive bleeding, dabigatran is the only DOAC with an FDA-approved antidote: idarucizumab (Praxbind). However, a reversal agent for the other DOACs, andexanet, is expected to gain regulatory approval this spring.
If you’re taking any of the blood thinners, keep in mind that you can still stop bleeding from a cut or other visible injury by applying pressure. The greater concern with the use of blood thinners is major gastrointestinal or intracranial (brain) bleeding, which can be life threatening. For this reason, experts recommend that patients taking blood thinners avoid contact sports or other activities that place you at risk for these severe bleeding events.
Factors to Consider
The DOACs have not been compared head-to-head in a clinical trial, so choosing one may depend on several factors, such as dosing frequency: Apixaban and dabigatran are taken twice a day, while edoxaban and rivaroxaban have once-daily dosing.
Warfarin offers protection for several days, whereas the DOACs have much shorter half-lives. Consequently, if you miss a dose of the newer drugs, especially those taken once a day, you could leave yourself unprotected. So, if you have trouble staying compliant with your medications, the newer blood thinners might not be for you.
Overall, discuss your need for anticoagulation and your choice of blood thinners with your physician, carefully considering the cost, convenience, safety and other pros and cons.