Anticoagulants

Lupus is a long-term (chronic) disease. In lupus, the immune system damages healthy tissue. It does this by making antibodies.¹

Antibodies are proteins that attach to certain substances so the immune system can destroy them. Antibodies typically target foreign substances – like viruses and bacteria – to protect the body from infection. But in people with lupus, antibodies target certain parts of healthy cells.¹

Who needs anticoagulants?

Up to half of people with lupus develop antibodies that target phospholipids and the proteins that bind to them (antiphospholipid antibodies). Phospholipids are a type of fat molecule that makes up cell membranes. People who have antiphospholipid antibodies are at higher risk for blood clots (thromboses) in the blood vessels.²

Blood clots can block blood flow and lead to serious complications like heart attack and stroke. If you test positive for antiphospholipid antibodies and develop a blood clot, you may be diagnosed with antiphospholipid syndrome. In this case, your doctor may prescribe an anticoagulant.^3,4

How do anticoagulants work?

Clotting is a natural and necessary process of solidifying blood. This process helps seal wounds to prevent infection and excessive bleeding. But too much clotting can be dangerous.^3,5

Commonly called blood thinners, anticoagulants are a type of drug that can help prevent blood clots. Clotting is also called coagulation. This is why blood thinners are technically called anticoagulants.⁵

These drugs can stop the body from forming clots or allow the body to break down existing clots. Some do this by inhibiting proteins in the blood that are involved in the clotting process. Others block the body’s ability to use substances it needs to form clots, like vitamin K.⁵

Examples

Several types of anticoagulant drugs are available to help people with lupus prevent blood clots. Commonly prescribed anticoagulants include the following.³

Warfarin (Coumadin)

Warfarin is the most common anticoagulant used for people with lupus. It works by blocking the action of vitamin K. Your body needs vitamin K to make certain clotting proteins. While taking warfarin, you should avoid eating large amounts of vitamin K.^3,5

Taking warfarin means you will need frequent blood testing to ensure the dose is correct. Your doctor will measure your international normalized ratio (INR) to monitor the effect of the warfarin and make sure your dose is correct.^3,5

Heparin

Heparin works more quickly than warfarin. It is typically given in an IV in hospitals or as a shot (injection) for short-term situations. There are 2 types of heparin:^3,5,6

• Unfractionated heparin (UFH) – This is the fastest-acting type of heparin. It is usually used in IV form in hospitals and requires constant monitoring to make sure the correct dose is given.
• Low-molecular-weight heparin (LMWH) – This type of heparin is given as a shot. It lasts longer and has more predictable results than UFH. It also requires less frequent monitoring than warfarin or UFH. You may even be able to give it to yourself at home. Examples of LMWH include enoxaparin (Lovenox®), danaparoid (Orgaran®), and dalteparin (Fragmin®).

A synthetic drug called fondaparinux (Arixtra®) works in the same way that heparin does. It is not as strong as heparin, so it works over a longer period to prevent blood clots. It also may be combined with other blood thinners to treat existing clots.^3,5

Direct oral anticoagulants (DOACs)

These drugs work by directly blocking substances necessary for clotting. They do not require as many blood tests as warfarin or heparin, making them more convenient for some people. Available DOACs include:^3,5,7

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

What are the possible side effects?

Side effects can vary depending on the specific drug you are taking. The most common side effect of blood thinners is uncontrolled bleeding. This bleeding may be generally harmless, like a bruise or a nosebleed. Or it may occur in an organ and lead to more severe symptoms and complications.^3,5

Other side effects of anticoagulants may include:^3,8,9

• Skin tissue decay (gangrene)
• Low platelet count (thrombocytopenia)
• Bloating
• Diarrhea
• Yellowing of the eyes or skin (jaundice)
• Skin rash
• Hair loss

These are not all the possible side effects of anticoagulant drugs. Talk to your doctor about what to expect when taking anticoagulants. You also should call your doctor if you have any changes that concern you when taking an anticoagulant.

Other things to know

If you have been diagnosed with lupus, your doctor will likely prescribe hydroxychloroquine (Plaquenil®). This is an antimalarial drug that, among other things, helps prevent excessive blood clotting. Your doctor also might recommend taking low-dose aspirin to prevent blood clots if you have not previously had a clot. And if you develop a clot, your doctor may prescribe a blood thinner.⁴

Dosage of anticoagulants is highly personal and must be regularly monitored and adjusted if necessary. Determining the correct dose of a blood thinner is a balancing act. It should be enough to prevent blood clots but not enough to allow severe bleeding. Your doctor will monitor you as needed.^3,5

Certain health conditions make it unsafe to take certain blood thinners. For example, people with kidney or liver problems may not be able to take DOACs. And some people should not take anticoagulants at all. This includes people who have:⁵

• Had a recent major injury or surgery
• Certain blood clotting disorders
• A history of bleeding in the brain, such as a stroke or aneurysm
• End-stage liver disease

Warfarin may cause damage to an unborn child. Tell your doctor if you are pregnant or planning to become pregnant. You may be able to take heparin while you are pregnant.^8-10

You should not smoke or take certain other drugs if you are taking an anticoagulant. Before beginning treatment for lupus, tell your doctor about all your health conditions and any other drugs, vitamins, or supplements you take. This includes over-the-counter drugs.³