Medication Treatment Options for Blood Clots

Medicines can be used both to prevent blood clots and to treat them. Medicines to prevent blood clots are used primarily in two situations:

  • Medicines are used to prevent blood clots when a person is at especially high risk for having a blood clot. This may include the period of time following surgery for a hip or knee replacement, for example. This type of prevention therapy is usually temporary, lasting for several weeks.
  • Medicines may also be used to prevent a blood clot from coming back in a person who has already had a blood clot. This type of therapy may be long-term, lasting six months or longer.

The type of medicine that is used to treat or prevent blood clots is known as a blood thinner. It is important to carefully take these medicines as directed by the physician or prescriber. Missing doses of medicine can increase the risk of a blood clot. On the other hand, taking too much of these medicines can increase the risk of bleeding. Maintaining the proper balance of medicine is important to avoid both of these problems.


Types of Medicines to Prevent and Treat Blood Clots

Broadly speaking, two types of blood thinner medicines are available for managing blood clots. Injectable heparin medicines are usually given when immediate or short-term therapy is needed. Oral warfarin is used when therapy is needed for a longer duration. Since warfarin usually takes at least a week to provide full benefits, heparin therapy is usually given along with warfarin for the first week or so until the full benefits of the warfarin are achieved.

Here are links to general information about blood thinning medicines.


Specific Blood Thinner Medicines

Unfractionated heparin
Heparin is a mixture of molecules of varying size. It is administered by subcutaneous injection and usually given every eight to twelve hours.
Get more information about Heparin
Low-molecular-weight heparins
Low-molecular-weight heparins are derived from unfractionated heparin, but are processed to have smaller and more uniform particle sizes. This results in better and more consistent absorption from the subcutaneous injection site. Enoxaparin is the product with the most extensive clinical trial research. Dalteparin and tinzaparin are other products in this class. Low-molecular-weight heparins are administered every 12 to 24 hours.
Get more information on enoxaparin (Lovenox®)
Get more information on dalteparin (Fragmin®)
Fondaparinux is a synthetic injectable blood thinner that is not derived from heparin. It is usually given once daily by subcutaneous injection.
Warfarin (Coumadin®)
Warfarin is an oral blood thinner that is usually taken once daily. It usually takes about one week before the full benefits of this blood thinning medicine are obtained. It is important to take this medicine according to the directions of the physician or prescriber. Warfarin can interact with certain other medicines and with certain foods.
Get more information on Warfarin.