What are these medicines? — These are prescription medicines that make your blood less likely to clot. "Oral" means medicine you take as a pill. There are other medicines that are given as a shot or through a thin tube that goes into a vein, called an "IV."
Medicines used to prevent or treat blood clots are also known as "anticoagulants" or "blood thinners." But they do not actually thin the blood.
There are several oral medicines used to prevent or treat blood clots. They include:
Apixaban (brand name: Eliquis)
Dabigatran (brand name: Pradaxa)
Edoxaban (brand names: Savaysa, Lixiana)
Rivaroxaban (brand name: Xarelto)
Warfarin (brand names: Coumadin, Jantoven)
Apixaban, dabigatran, edoxaban, and rivaroxaban are also called "direct oral anticoagulants." Each of these medicines blocks the function of a specific clotting factor. (Clotting factors are proteins in the blood that help it to clot.) Warfarin is also called a "vitamin K antagonist." It blocks the body's use of vitamin K in making some of the clotting factors.
Why would I need one of these medicines? — The main reasons doctors prescribe these medicines are to prevent blood clots or to treat blood clots that have already formed.
Doctors prescribe these medicines to prevent blood clots in:
People who have a heart rhythm problem called "atrial fibrillation" – In people with this condition, the medicine helps lower the chances of forming a blood clot in the heart. A blood clot in the heart can cause a stroke.
People who have had hip or knee replacement surgery – The medicine helps prevent a blood clot in the legs (called a "deep vein thrombosis" or "DVT") or the lungs (called a "pulmonary embolism" or "PE").
People who have a mechanical heart valve – This is a device used to replace a damaged heart valve.
Other people who are at high risk of having a blood clot.
Nothing can completely prevent all blood clots, but these medicines can make clots less likely to form.
Doctors also prescribe these medicines for people who have already had a clot, to prevent more problems. This includes:
People who have had a stroke related to atrial fibrillation
People who have had a DVT or PE
People who have had a blood clot in another part of the body
How do these medicines help? — These medicines do not dissolve clots, but they keep them from growing bigger and moving to another part of the body. If a clot moves to a lung or to the brain, it can cause serious problems. These medicines lower the chances that the blood clot might get bigger or move to another part of the body, and they lower the chances of new clots forming.
What are the differences among these medicines? — Each medicine is different in terms of the dose, how often you take it, the cost, and how your diet or other medicines might affect it.
The table answers some common questions about the differences (table 1). Some of the main differences include:
How often you need to get blood tests – If you take apixaban, dabigatran, edoxaban, or rivaroxaban, you will not need regular blood tests.
If you take warfarin, you will need to get your blood tested on a regular schedule to check how it is clotting. This is important in order to make sure you are always getting the dose you need.
How often you take the pills – This depends on which medicine you take and why your doctor prescribed it. In general, warfarin, edoxaban, and rivaroxaban are taken once a day. Apixaban and dabigatran are usually taken twice a day (table 1). If you are taking the pills to treat a new blood clot, the first week or more of treatment might be different. Your doctor or pharmacist will tell you how many times you need to take your medicine each day.
Whether you need to change your diet – This is especially important if you take warfarin, as you will need to be careful about how much vitamin K you eat. If the amount of vitamin K in your diet changes from day to day, this can make warfarin not work as well.
The risk of bleeding – Most kinds of bleeding – including bleeding in the brain – are less likely with apixaban, dabigatran, edoxaban, and rivaroxaban than they are with warfarin. But all of these medicines raise your risk of bleeding more than normal. This can be serious internal bleeding, like bleeding in the brain or the intestines, or external bleeding, like after you get a cut.
What happens if I miss a dose – If you miss a dose of apixaban, dabigatran, edoxaban, or rivaroxaban, you might not be as well protected from blood clots because these medicines leave your system quickly. If you miss a dose of warfarin, it will still work correctly. Ask your doctor or pharmacist what to do if you miss a dose of your medicine.
Which medicine is right for me? — Your doctor can talk to you about your condition, options, and preferences. For some people, warfarin is the best choice. This includes people with a mechanical heart valve or people with a condition called "antiphospholipid syndrome."
For others, one of the other medicines might be a better choice.
In women who are pregnant, doctors do not recommend any of these medicines. Pregnant women who need to take a medicine to prevent or treat blood clots have to take a different medicine that comes in a shot.
For more detailed information about your medicines, ask your doctor or nurse for the patient hand-out from Lexicomp available through UpToDate. It explains how to use each medicine, describes its possible side effects, and lists other medicines or foods that can affect how it works.
All topics are updated as new evidence becomes available and our peer review process is complete.
This topic retrieved from UpToDate on: Mar 30, 2020.
Topic 16265 Version 22.0
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