Factor Xa Inhibitors for AFib

Medically Reviewed by James Beckerman, MD, FACC on June 28, 2022
4 min read

If you live with persistent or permanent atrial fibrillation (sometimes called AF or AFib), a type of irregular heartbeat, you probably take a blood thinner to reduce your risk of stroke and blood clots. Research shows that a newer class of blood thinner called a factor Xa inhibitor is a good option for long-term use.

All blood thinners, or anticoagulants, help prevent blood clots. Factor Xa inhibitors work by targeting a specific enzyme in your blood’s clotting process.

They have fewer side effects than the blood thinner warfarin, which has long been a standard treatment to reduce stroke risk in AFib. You also won’t need to get routine blood monitoring, which you do with warfarin.

That doesn’t mean factor Xa inhibitors are your best bet to reduce the risk of complications from AFib. The treatment you need will depend on several things, including your general health, your AFib, and your preferences.

The first thing you may wonder when you see the phrase “factor Xa inhibitors” is what that first word means. Xa is another way of writing “10a.” Clotting factor 10a is an enzyme your body uses to form blood clots, and that’s what these drugs target.

Three factor Xa inhibitors approved for AFib are:

  • Apixaban (Eliquis), a twice-daily drug
  • Edoxaban (Savaysa), a once-daily drug
  • Rivaroxaban (Xarelto), a once-daily drug

They’re considered new or newer anticoagulants, but they’ve been around for years as an alternative to warfarin. They’re approved for nonvalvular AFib – meaning your AFib isn’t related to a heart-valve problem.

These drugs are safe and effective, but they’re not right for everyone. Here's what your doctor will consider before prescribing a blood thinner for AFib.

Your type of AFib: This cardiac arrhythmia (heartbeat irregularity) can be fleeting, permanent, or something between.

  • Occasional (paroxysmal). This type comes and goes. Symptoms may last for a few minutes or a few hours. You may need treatment to get your heart back to a normal rhythm.
  • Persistent. You need treatment to restore and maintain a normal heart rhythm, and there’s hope that your heartbeat will eventually return to normal. Until then, blood thinners, including factor Xa inhibitors, can reduce your chances of serious complications.
  • Permanent. You’ll need medications to control your heart rate and to prevent blood clots. People with permanent AFib can take factor Xa inhibitors long term.

When it comes to blood thinner medications for AFib, you have good options: an older mainstay treatment or newer options with a few advantages.

Warfarin. This older blood thinner is a type called a vitamin-K antagonist. Warfarin has been in use since the 1950s, so doctors know a lot about it. On the plus side, it’s an effective, safe, and affordable anticoagulant that can be used for any type of AFib. On the minus side, it interacts with many foods and medications. Plus, you’ll need routine blood tests to make sure you’re taking the right dose for your body.

Factor Xa inhibitors. Research shows these drugs are as safe and effective as warfarin for AFib (and even more effective than warfarin if you’re older than 75). Factor Xa inhibitors may also be easier to stick with than warfarin, because they have these advantages:

  • Less likelihood of drug interactions
  • No dietary restrictions
  • Less need for routine monitoring

Factor Xa inhibitors may also be safer than warfarin, due to a lower risk of bleeding. But these advantages come at a cost. Factor Xa inhibitors are much more expensive than warfarin – though you do avoid the cost of blood tests and other aspects of routine tracking.

All drugs have potential risks, and factor Xa inhibitors are no exception. But if you heard or read about concerns that factor Xa inhibitors can’t be reversed in the body, rest assured that’s not the case. Doctors can give you medication that reverses the drugs’ anticoagulant effects in an emergency, like uncontrolled bleeding. The first “antidote” was approved in 2018.

Factor Xa inhibitors do have real risks, though.

Excessive bleeding. Bleeding is a serious concern with blood thinners. Before taking a factor Xa inhibitor, you should have your bleeding risk assessed. If your doctor doesn’t do this as part of your AFib treatment plan, don’t hesitate to ask.

Bruising. You may need to be more alert than usual about protecting yourself from physical injury, such as during sports or moving furniture around the house.

Overdose. Anyone can take too much of a drug. If you take too much of a factor Xa inhibitor, symptoms such as these may be related to bleeding somewhere in your body:

Blood clots or reduced blood flow to the brain. These serious health problems are most likely to happen if you decide on your own to stop taking your medication. If you want to make a change to your treatment plan, be sure to talk it over with your doctor first.