Medications
Anticoagulant medicines are the main form of treatment
for
deep vein thrombosis. Anticoagulants affect the way
blood clots in the body.
Medication Choices
Anticoagulants
Anticoagulants can prevent new clots from forming and prevent
existing clots from getting larger; however, they do not break up or dissolve
existing blood clots.
Anticoagulants are used to:
- Treat existing deep vein
thrombosis.
- Prevent a blood clot that can develop after some types
of surgery.
- Prevent blood clots in people who are at high risk
(such as those who have had previous clots).
Anticoagulants that are used to prevent and treat deep vein
thrombosis include:
- Heparin. The two
types of heparin are:
- Low-molecular-weight
heparin (LMWH). This type can be self-injected at home, which is more
convenient.
- Unfractionated heparin (UH). This type
is given through a vein (IV) or through an injection under the skin. UH
typically requires regular monitoring and is usually given in the hospital.
- Warfarin (such as
Coumadin), an
oral
anticoagulant.
Heparin acts immediately, while warfarin takes several days to
become effective. Heparin will be discontinued when warfarin is at a
therapeutic level.
Low-molecular-weight heparin (LMWH) and unfractionated heparin
(UH) are both effective at treating deep vein thrombosis. LMWH is typically
preferred over UH, because LMWH can be given at home and typically does not
require monitoring with blood tests..
The ideal length of time to continue treatment with an oral
anticoagulant varies and is still being researched. In general, treatment of a
blood clot with oral anticoagulant medicines will continue for about 3 to 6
months. The length of time will vary based on your own health.
- If you have a short-term risk of deep vein
thrombosis because of surgery, treatment with oral anticoagulant medicines
usually lasts a shorter period of time.8
- If you have recurrent blood clots or continuing
risk factors (such as cancer), anticoagulant treatment usually continues as
long as those risk factors are present, which could be for the rest of your
life.8
- If you have
inherited blood-clotting disorders, you may need oral
anticoagulants indefinitely.6
Studies show that proper anticoagulant therapy reduces the rate
of recurrent blood clots from 25% to less then 5% in the first 3
months.9 When used to initially treat deep leg vein
thrombosis, heparin reduces the risk of developing deep vein blood clots and
fatal blood clots in the lungs (pulmonary embolism) by 60% to
70%.10 Some people may take low-molecular-weight
heparin (LMWH) long-term instead of warfarin.
After your initial treatment with warfarin, your doctor may
recommend that you take warfarin on an ongoing basis to prevent deep vein clots
from recurring.2
If you take warfarin, don't suddenly change your intake of
foods that are rich in vitamin K. Vitamin K can interfere with the action of
anticoagulants, making it more likely that your blood will clot. For more
information, see:
Eating a steady amount of vitamin K when you
take warfarin (Coumadin).
What To Think About
Aspirin may help prevent blood clots and reduce the risk of
pulmonary embolism. But experts do not agree on how well aspirin works for
preventing pulmonary embolism.
Thrombolytics are sometimes used in certain situations to treat
deep vein thrombosis. But thrombolytics have a high risk of causing bleeding.
They may be used if you have problems when you take heparin.
People with other illnesses such as liver or kidney problems, a
recent stroke, recent surgery, inherited bleeding disorders, a bleeding ulcer,
or other internal bleeding may not be able to take anticoagulants or
thrombolytic medications.
Pregnant woman with deep vein thrombosis should not
use warfarin. Only unfractionated heparin or low-molecular-weight heparin
should be given.