Blood Thinners continued...
Common blood thinners used in AFib patients are:
- Coumadin (warfarin)
- Pradaxa (dabigatran)
- Xarelto (rivaroxaban)
All of these are pills you take every day. They target factors that your blood needs to form clots, but they work a little differently. Pradaxa and Xarelto work directly on thrombin, the blood’s central clotting agent, while Coumadin competes with vitamin K, which your liver needs to create the proteins that help blood to clot.
Because they inhibit the blood’s ability to clot, these drugs also carry the risk of bleeding. But since Coumadin’s effects are more variable based on a person’s size, weight, gender, and other medications being used, patients taking Coumadin have to get regular blood tests (usually at least monthly) to make sure they don’t have too much or too little of the drug in their system. Pradaxa and Xarelto, on the other hand, are more predictable and don't require the same frequent blood testing.
While Coumadin has been around longer, periodic blood tests to check on Coumadin levels may be less desirable. Pradaxa (twice a day) and Xarelto (once a day) may be more convenient, but can also be more costly. "Pradaxa also has certain bleeding risks that you don’t have with Coumadin; if you’re in a traumatic accident, the drug’s effects may be more difficult to reverse," Wylie adds.
Xarelto is approved to prevent stroke in patients with AFib not caused by a heart valve problem. It also raises the risk for bleeding. But Xarelto can also raise the risk of stroke if people stop taking it without medical supervision. That's the main warning in the "black box" on the Xarelto label. A black box warning is the FDA's strongest warning.
Xarelto had previously been approved to prevent blood clots in patients receiving hip and knee replacements.
Eliquis is approved only for use in people with AFib that is not caused by a heart valve problem. People with prosthetic heart valves should not take Eliquis. Study results showed that people who took Eliquis twice a day had 21% fewer strokes than those on the blood thinner warfarin. Monthly blood tests are not required for those taking the drug. Eliquis is now the third new blood thinner to be approved as an alternative to warfarin since 2010.