Direct thrombin inhibitors (only used in the hospital)
How It Works
Anticoagulants are often called blood
thinners, but they don't really thin blood. They work by increasing the time it
takes for a blood clot to form. This prevents an existing clot from increasing
in size, thereby preventing a
heart attack or
Why It Is Used
Anticoagulants are not typically used to treat coronary artery disease. But you might take them after having angioplasty or bypass surgery. You might take an anticoagulant if you also have atrial fibrillation or other complications.
How Well It Works
Anticoagulants lower the risk of problems caused by blood clots, such as a heart attack or stroke.1
All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.
Here are some important things to think about:
Usually the benefits of the medicine are more important than any minor side effects.
Side effects may go away after you take the medicine for a while.
If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.
Bleeding: Call 911 or other emergency services right away if:
You cough up blood.
You vomit blood or what looks like coffee grounds.
You pass maroon or very bloody stools.
You have a sudden, severe headache that is different from past headaches. (It may be a sign of bleeding in the brain.)
Call your doctor right away if you have unusual bleeding:
You have new bruises or blood spots under your skin.
You have a nosebleed that doesn't stop quickly.
Your gums bleed when you brush your teeth.
You have blood in your urine.
Your stools are black and look like tar or have streaks of blood.
You have heavy period bleeding or vaginal bleeding when you are not having your period.
If you are injured, apply pressure to stop the bleeding. Realize that it
will take longer than you are used to for the bleeding to stop. If you can't get the bleeding to stop, call your doctor.
Allergic reaction: Call 911 or other emergency services right away if you have:
Swelling of your face, lips, tongue, or throat.
Call your doctor if you have:
Heparin: Side effects often happen at injection sites. These side effects include:
Warfarin: Other side effects include:
See Drug Reference for a full list of side effects. (Drug Reference is
not available in all systems.)
What To Think About
When you take anticoagulants, you need to take extra steps to avoid bleeding problems.
Long-term use of heparin is not typically
recommended. It requires one or two injections each day. And long-term use is linked with
Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.
There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.
Advice for women
Do not take warfarin if you are pregnant. Warfarin can cause miscarriage or birth defects. If you are taking warfarin, talk to your doctor about how you can prevent pregnancy.
If you think you might be pregnant: Call your doctor. If you are pregnant, you will take heparin during your pregnancy.
If you plan on getting pregnant: Talk with your doctor. You and your doctor will decide which medicine you will take—warfarin or heparin—while trying to get pregnant.
If you are pregnant: You will take heparin during your pregnancy. Heparin has not been shown to affect the fetus.
Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.
Antithrombotic drugs (2011). Treatment Guidelines From The Medical Letter, 9(110): 61–66.
How this information was developed to help you make better health decisions.