Blood Thinners (Anticoagulants) and Atrial Fibrillation

Atrial fibrillation (AFib) is a heart condition in which the heartbeat becomes too fast or irregular. AFib can lead to stroke, so doctors try to treat it as quickly as possible. One of the ways AFib is treated is to prescribe blood thinners. Your doctor may also call these drugs anticoagulants (ann-tee-co-AG-you-lints).1

The abnormal heartbeat of atrial fibrillation can cause blood to back up in 1 area of the heart and cause blood clots. The blood clots can then break off and travel from the heart to the brain, which causes a stroke. The blood clots may also move to other areas of the body, causing damage.1

Blood thinners are a type of drug that make it harder for new clots to form or existing clots from getting bigger.1

Types of blood thinners

An older type of blood thinner is warfarin (Coumadin®, Jantoven®). Warfarin is a powerful drug that can cause bleeding in the brain if too much is taken. It also interacts with many other drugs, which can increase or decrease warfarin levels in the body.1

To avoid complications, your doctor will require regular blood tests. These tests make sure you are taking the right amount of warfarin to prevent blood clots without taking too much. Your dose of warfarin may need to change depending on your blood test results.1,2

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A newer group of blood thinners are called direct-acting oral anticoagulants or DOACs. DOACs have fewer drug and food interactions than warfarin. You usually do not need regular blood tests to monitor the level of these drugs in your body.1,2

Examples of DOACs are:2

  • Apixaban (Eliquis®)
  • Dabigatran (Pradaxa®)
  • Edoxaban (Savaysa®)
  • Rivaroxaban (Xarelto®)

Side effects can vary depending on the specific drug you are taking. Excessive bleeding is not the only possible side effect of taking blood thinners. Talk to your doctor about what to expect when taking blood thinners. You also should call your doctor if you have any changes that concern you when taking a blood thinner.1

Who should take a blood thinner?

Doctors use a scoring system to decide who would most benefit from taking a blood thinner. Points are given as follows:2

2 points each for:

  • Age 75 or older
  • History of stroke or TIA (transient ischemic attack)

1 point each for:

  • Heart failure
  • Diabetes
  • High blood pressure
  • Heart attack or having a stent in your heart or leg
  • Age 65 to 74
  • Being female

Men with 2 points and women with 3 points generally benefit from taking a blood thinner.2

Benefits and risks of blood thinners

The biggest benefit to taking a blood thinner is reducing your chance of a stroke. Strokes can be serious. a stroke can cause you to lose your sight, your ability to speak and walk, or even death. But, while blood thinners help reduce your chances of stroke, they may also make you bleed more easily.2

Most people who take blood thinners may find they bruise more easily and it takes longer for their cuts to stop bleeding. Their gums may also bleed. For others, serious bleeding can be a problem. Signs of problem bleeding include:2

  • Dark (red or pink) urine
  • Nosebleeds
  • Bleeding into joints

If you vomit blood or notice bloody, very dark feces (poop), it may mean you are bleeding in your stomach or intestines. A sudden headache may mean bleeding inside your head. Call your doctor or 911 right away if you notice any of these signs of serious bleeding.2

Other things to know

Take your blood thinner as prescribed. Stopping a blood thinner suddenly can increase your risk of stroke.1

Regular exercise is important to maintain your health. But avoid contact sports and activities where you have a higher risk of injury if you take blood thinners.2

Do not take other drugs that tend to increase bleeding without talking with your doctor. Such drugs include:2

  • Aspirin
  • Drugs that contain aspirin (such as Alka-Seltzer®, Aspergum®, and Bufferin®)
  • NSAIDs (Advil®, Motrin®)

Drinking alcohol may also increase your bleeding risk. So stick to 8 or fewer drinks per week.2

Wear a medical alert bracelet and keep an anticoagulant alert card with you at all times if you take a blood thinner. This will help emergency responders treat you correctly.1

Before beginning to take any blood thinner, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you take. This includes over-the-counter drugs.

Treatment results and side effects can vary from person to person. This treatment information is not meant to replace professional medical advice. Talk to your doctor about what to expect before starting and while taking any treatment.

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