Also known as thrombolytics, clot busters are medications used to break up a blood clot. Other medications are able to prevent a blood clot from forming or growing (anticoagulants), but clot busters are the only medications currently available that can actually destroy an existing blood clot. They are often used in emergency situations, particularly among people suffering from the most common form of stroke or heart attack. If administered early in these situations, clot busters have the proven ability to lessen the long-term damage from stroke or heart attack. Clot-busting drugs may also be used to treat pulmonary embolisms and clots that form around artificial heart valves.

Administering clot busters is complex and usually done through an intravenous (I.V.) line in the arm by hospital personnel. Alternatively, clot busters may be administered directly to the site of the clot using a thin tube (catheter), allowing for a greater dose of the drug with fewer potential side effects. Paramedics are also increasingly giving these medications (under a physician’s direction) while a patient is en route to the hospital.

Although clot busters can save the life of a person having a heart attack or the most common type of stroke, there is also a higher risk of bleeding associated with clot busters than with anticoagulants. Clot busters are most effective when given within a few hours after the onset of symptoms. Therefore, it is important to recognize the signs and symptoms early.