Factor Xa inhibitors are a type of anticoagulant, or blood thinner. They’re a short- and long-term therapy for venous thromboembolism (VTE), which includes deep vein thrombosis (DVT) and pulmonary embolism (PE).
Talk to your doctor if you have a history of blood clots. VTE is dangerous but treatable. They’ll let you know if factor Xa inhibitors are right for you.
What Are Factor Xa Inhibitors?
They’re in a class of blood thinners called direct oral anticoagulants, or DOACs. They work by targeting tiny molecules called factor Xa, a substance that helps the platelets, cells, and proteins in your blood stick together, or clot.
Factor Xa inhibitors block the final step needed to make thrombin. That’s an enzyme in your blood that turns something called fibrinogen into fibrin, which helps you close up wounds. People whose bodies make a lot of thrombin seem to be more likely to have recurrent DVT or PE.
You can get factor Xa inhibitors with a prescription from your doctor. Examples include:
Who Needs Them?
Your doctor might suggest factor Xa inhibitors if you’ve had VTE and there’s a strong chance you’ll have another harmful blood clot in the future.
Anyone can get DVT or PE. But certain things raise the odds it’ll happen again, including:
- Prior blood clots
- Active cancer or chemotherapy treatments
- A genetic condition (thrombophilia)
- Obesity
- Smoking
Factor Xa inhibitors are also used to prevent blood clots in the heart caused by an abnormal heart rhythm, or atrial fibrillation.
These drugs are sometimes paired with aspirin to lower the chances of a heart attack or stroke in people who have coronary artery disease, or heart disease.
Who Can and Can’t Take Them?
Factor Xa inhibitors are approved for most adults ages 18 and older. Rivaroxaban is OK for children with a history of DVT or PE.
But these drugs may not be right for everyone. Tell your doctor if:
- You’ve had an allergic reaction to any medication
- You’re pregnant or trying to have a baby
- You have liver or kidney problems
- You’ve had heart valve replacement surgery
These anticoagulants may not be safe if you have:
- An injury that makes you bleed a lot
- A stomach ulcer
- Antiphospholipid syndrome
- A recent spinal injury or spinal surgery
We need more research to know how well factor Xa inhibitors work in people with a very high body mass index.
How Do You Take Them?
Factor Xa inhibitors are usually pills you take once or twice a day. They work within a few hours. Your doctor will tell you the dose and schedule that’s right for you. It’s best to take your medicine at the same time every day.
Tell your doctor if you have trouble swallowing pills. You may be able to crush the tablets and mix them with liquid or soft foods, including:
- Water
- Apple juice
- Applesauce
- Liquid mixture for a gastric tube
Always take rivaroxaban with a meal or snack. That’ll help you absorb it better. You can take apixaban and edoxaban with or without food.
Take your medication exactly as prescribed. Factor Xa inhibitors can leave your bloodstream really fast. That means your chances of blood clots go up if you miss a dose or stop taking them suddenly. Ask your doctor if you have any questions about how to take your medication.
What Are the Risks?
Factor Xa inhibitors are generally considered safe to take for months or years.
Anticoagulants are a good way to lower your odds of another DVT. But they can make it harder for your body to stop bleeding quickly. These risks may be higher in people with certain kinds of stomach, intestinal, or genitourinary tract cancers.
Factor Xa inhibitors may raise your chances of:
- Nosebleeds
- Heavy periods
- Bleeding gums
- Bruising
- Major bleeding
To stay safe, be careful around objects that might hurt you. Go easy when you brush your teeth or floss, and gently blow your nose instead of picking it.
Some kinds of bleeding may be harmless. But tell your doctor right away if you have a cut or scrape that won’t heal or you notice a lot of uncontrolled bleeding. That can be a medical emergency.
Other signs of bleeding problems include the following:
- Black or bloody poop
- Blood in your urine
- Headache or dizziness
- Pain or swelling in a joint
- Small red spots on your skin
Are There Other Side Effects?
You may have some unwanted symptoms on top of bleeding easily. They may not bother you very much, and they usually go away as your body gets used to the medicine.
Common side effects might include:
- Tiredness or lack of energy
- Shortness of breath
- Irregular heartbeats
- Pale skin
- Dizziness or feeling sick to your stomach
Factor Xa inhibitors may cause a serious allergic reaction in some people. That’s called anaphylaxis. Get medical help right away if you take your medicine and notice the following:
How Long Do You Take Them?
It’s common to get anticoagulant therapy for at least 3 to 6 months after a serious blood clot. But you’ll likely need extended treatment if you have DVT risk factors that’ll stick around for a while or won’t ever go away.
You may need factor Xa inhibitors for a set period of time or the rest of your life. It depends on what caused your blood clot in the first place. Your doctor will also consider your age, other health conditions, and what might happen if they raise your chances of bleeding for a long time.
How Well Do They Work?
Studies show that factor Xa inhibitors reduce recurrent VTE just as well or better than standard therapies. That includes drugs in the same class, such as low molecular weight heparin (LMWH) and vitamin K antagonists.
There’s some evidence that apixaban may lower the rate of new blood clots more than other DOACs. We need more research to know for sure.
In general, the chances of increased bleeding may be about the same or less with factor Xa inhibitors, when compared to other anticoagulants. But some research shows that major bleeding – the kind that sends you to the hospital – may be more likely on DOACs, when compared to LMWH.
Experts think anticoagulants like factor Xa inhibitors may be preferred over older DVT treatments because:
- Pills are easier to take than shots.
- They work the same in most everyone.
- You don’t need ongoing bloodwork to check how they’re working.
- They don’t interact with many other drugs.
Ask your doctor to go over all the pros and cons of factor Xa inhibitors or any other anticoagulant therapies. Bring up any concerns about increased bleeding, especially if you have cancer-related VTE.
Can You Take Them With Other Medications?
It’s not safe to take factor Xa inhibitors with another anticoagulant or blood thinner. Your doctor will let you know how to switch medications safely if you’re already taking one.
Some substances may affect how factor Xa inhibitors work. Talk to your doctor about all the drugs you’re taking. That includes supplements and vitamins.
It may not be safe to take factor Xa inhibitors with:
- Antifungal or antibacterial medication
- Antiviral drugs to treat HIV
- Anti-seizure medication
- Non-steroidal anti-inflammatory drugs (NSAIDs)
- St. John’s wort or other herbal remedies
In Case of Emergency
It’s a good idea to carry an anticoagulant alert card with you. Show it to all your doctors. That includes your dentist, surgeon, or anyone who might give you a shot or exam. They may need to take extra steps to prevent bleeding.
Your anticoagulant alert card might include information such as:
- Signs and symptoms of emergency bleeding
- Name and dose of your medication
- Why you take an anticoagulant
- Emergency contact name and number
- Your doctor’s name and number
Visit the website of the company that makes your factor Xa inhibitor. They may have an alert card you can download and print. Talk to your doctor or pharmacist for more information.
