Blood Thinners continued...
Common blood thinners used in AFib patients are:
- Apixaban (Eliquis)
- Dabigatran (Pradaxa)
- Edoxaban (Savaysa)
- Rivaroxaban (Xarelto)
- Warfarin (Coumadin)
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. Dabigatran works directly on thrombin, the blood’s central clotting agent, for example, while warfarin 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 warfarin’s effects are more variable based on a person’s size, weight, gender, and other medications being used, patients taking it 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. Dabigatran and rivaroxaban, on the other hand, are more predictable and don't require the same frequent blood testing.
While warfarin has been around longer, periodic blood tests to check on its blood levels may be less desirable. Dabigatran (twice a day) and rivaroxaban (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.
Dabigatran and rivaroxaban are approved to prevent stroke in patients with AFib not caused by a heart valve problem. They also raise the risk for bleeding. But they 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 drugs' labels. A black box warning is the FDA's strongest warning.
Apixaban 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 it. Study results showed that people who took apixaban 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.
Edoxaban is also approved for use in people with AFib that is not caused by a heart valve problem. Edoxaban was tested against warfarin in over 21,000 people. Edoxaban was shown to be similar to warfarin in the reduction of the risk of stroke with a lower risk of bleeding.