What are clot busters?
Clot busters (thrombolytics) are a type of medication used to dissolve blood clots. In most cases your body can break down and reabsorb a DVT blood clot on its own. However, your doctor may use clot busters to speed up this process if you have a large clot that is causing heart or breathing problems. Because clot busters increase the risk of dangerous bleeding, they will only be used when absolutely necessary.
The most common type of clot-busting drug used to treat DVT or PE is called tissue plasminogen activator (tPA), but other medications may also be used. tPA is also used to break up clots that caused a blocked-vessel stroke or heart attack.
See also: Immediate Stroke Treatment: tPA
How are clot-busters given?
Clot busters are usually given as an injection in the hospital. In some cases, the medication may be injected directly onto the clot during a procedure called catheter-directed thrombolysis. In this procedure, a long, thin tube called a catheter is inserted into a small cut in your groin or arm and guided through your blood vessels to the location of the clot using X-ray images. Once in place, the clot-busting drug is released onto the clot to dissolve it and restore blood flow. To learn more about the catheterization procedure, see cardiac catheterization.
Who might need clot busters to treat DVT or PE?
For most women with DVT or PE, blood-thinning drugs (such as LMWH) are enough to prevent further blood clots and reduce the risk of dying. However, some women with large blood clots, especially those that have broken off to block an artery in the lungs ( pulmonary embolism) may benefit from clot busters to speed the breakdown of the clot.
Clot busters are rarely used to treat DVT, but women with extensive blood clots in the veins of the abdomen or upper legs may benefit from clot busters as long as they have a very low risk of bleeding problems.9 Because blood clots that travel to the lungs are more likely to cause serious complications, clot busters are more often used to treat pulmonary embolism. You may benefit from clot busters if you have been diagnosed with pulmonary embolism and you:9
- Lose consciousness
- Are not getting enough oxygen because the clot is blocking blood flow to a large part of the lungs
- Have very low blood pressure ( hypotension)
- Develop heart failure
- Already have heart or lung disease
Who should not receive clot busters?
You should not receive clot busters if you are currently bleeding (such as because of a recent injury or surgery, stomach ulcer, or bleeding stroke) or if you have other conditions that make bleeding more likely. Certain other medications, such as warfarin and aspirin, can make bleeding problems worse when combined with clot busters.
If you are unable to take clot busters because the risk of bleeding is too high, the clot may need to be removed with surgery or other methods. See DVT Treatment Overview to learn more.
What are the risks of clot busters?
As with other drugs to treat DVT and PE, the main risk of clot busters is excess bleeding. Because of this risk, clot busters are only used in life-threatening situations. If you are being treated with clot busters, your doctor has determined that the benefits of restoring blood flow quickly outweigh any bleeding risks.
If you are having a procedure in which the clot buster is injected directly onto the clot through a catheter, there is a small risk of complications including:
- Infection of the incision where the catheter was inserted
- Damage to your arteries from the catheter
- An allergic reaction to the X-ray dye used in the test
- Hale TW. Medications and Mothers' Milk. 13 ed; 2008.
- Snow V, Qaseem A, Barry P, et al. Management of venous thromboembolism: a clinical practice guideline from the American College of Physicians and the American Academy of Family Physicians. Ann Fam Med. Jan-Feb 2007;5(1):74-80.
- Segal JB, Eng J, Jenckes MW. Diagnosis and Treatment of Deep Venous Thrombosis and Pulmonary Embolism. Evidence Report/ Technology Assessment Number 68. . Rockville, MD: Agency for Healthcare Research and Quality; March 2003. AHRQ Pulblication No. 03-E106.
- Hirsh J, Anand SS, Halperin JL, Fuster V. AHA Scientific Statement: Guide to anticoagulant therapy: heparin: a statement for healthcare professionals from the American Heart Association. Arterioscler Thromb Vasc Biol. Jul 2001;21(7):E9-9.
- Hirsh J, Anand SS, Halperin JL, Fuster V. Guide to anticoagulant therapy: Heparin : a statement for healthcare professionals from the American Heart Association. Circulation. Jun 19 2001;103(24):2994-3018.
- Clagett GP, Reisch JS. Prevention of venous thromboembolism in general surgical patients. Results of meta-analysis. Ann Surg. Aug 1988;208(2):227-240.
- Sacco RL, Adams R, Albers G, et al. Guidelines for prevention of stroke in patients with ischemic stroke or transient ischemic attack: a statement for healthcare professionals from the American Heart Association/American Stroke Association Council on Stroke: co-sponsored by the Council on Cardiovascular Radiology and Intervention: the American Academy of Neurology affirms the value of this guideline. Circulation. Mar 14 2006;113(10):e409-449.
- Hirsh J, Fuster V, Ansell J, Halperin JL. American Heart Association/American College of Cardiology Foundation guide to warfarin therapy. Circulation. Apr 1 2003;107(12):1692-1711.
- Hirsh J, Hoak J. Management of Deep Vein Thrombosis and Pulmonary Embolism : A Statement for Healthcare Professionals From the Council on Thrombosis (in Consultation With the Council on Cardiovascular Radiology), American Heart Association. Circulation. June 15, 1996 1996;93(12):2212-2245.