Thrombolysis is the use of medication to dissolve blood clots. This may be for an emergency situation, like a heart attack, or to treat or prevent complications from conditions that can cause blood clots.

Thrombolysis is a potentially lifesaving treatment healthcare professionals use to break up or prevent blood clots.

Forming blood clots is your body’s way of stopping bleeding. But in some instances, blood clots can cause life threatening conditions, like a heart attack or kidney failure.

This article defines thrombolysis and explains what it involves. The article also goes into the potential risks and side effects of thrombolysis.

Thrombolytic therapy (thrombolysis) refers to the use of medication to dissolve blood clots. Healthcare professionals can also use thrombolysis to prevent the formation of new blood clots in people at high risk. People sometimes refer to thrombolytic drugs as “clot busters.”

Doctors can deliver these drugs through an intravenous (IV), a needle in your arm, or another body part. They can also deliver the drug directly into or near a blood clot with a catheter during a minimally invasive procedure. You can receive an anesthetic to put you under anesthesia for the procedure.

Healthcare professionals often use thrombolysis in emergency situations. For example, if you experience a heart attack or stroke, they may provide thrombolytic medications quickly to restore blood flow and oxygen to the heart or brain. Thrombolytic therapy is also an emergency treatment for an acute pulmonary embolism.

If you take blood thinners that don’t prevent or shrink blood clots effectively, a healthcare professional may switch you to a thrombolytic medication. They may also recommend thrombolysis to prevent emergencies by treating existing blood clots from conditions such as:

Various factors determine which procedure healthcare professionals may use to deliver thrombolytic drugs. Factors to consider include your:

  • condition that requires treatment
  • age
  • overall health
  • risk of complications, like heavy internal bleeding

Systemic thrombolysis

During systemic thrombolysis, you may receive thrombolytic drugs through an IV line attached to a needle in your arm. This delivery system enables the medications to travel throughout your body so they can dissolve clots.

Healthcare professionals typically use systemic thrombolysis in the case of a medical emergency, such as a stroke, heart attack, or pulmonary embolism.

Catheter-directed thrombolysis

Cather-directed thrombolysis is a minimally invasive procedure. Healthcare professionals perform the procedure once they give you an anesthetic to put you under anesthesia. They may schedule this procedure proactively to treat DVT and PAD blood clots.

During the procedure, they insert a thin, hollow tube called a catheter into a blood vessel through a tiny opening.

The catheter has a small camera and tools on its tip. A healthcare professional guides it into the clot by viewing X-ray images on a screen. The catheter then delivers thrombolytic medications directly into the clot.

In some cases, a healthcare professional may remove the clot manually with the tools on the catheter. This part of the procedure is a mechanical thrombectomy.

If they can’t remove the clot, they can keep the catheter in place to continually deliver medication until the clot dissolves. This may take anywhere from several hours to 2 days.

Thrombolysis vs. thrombectomy

Thrombolysis involves breaking up blood clots. Thrombectomy is a surgical procedure to remove (excise) a blood clot from an artery or vein. A healthcare professional may perform a thrombectomy during catheter-directed thrombolysis.

During a mechanical thrombectomy, a balloon catheter or mechanical device allows healthcare professionals to remove the blood clot manually, restoring blood flow.

Thrombolytic medications are in a class of drugs called serine proteases. Experts also refer to thrombolytics as fibrinolytic drugs.

These medications dissolve blood clots by separating and breaking apart the proteins (fibrins) that hold them intact.

Several types of thrombolytic drugs are available. Their cost, effectiveness, and risks vary. A healthcare professional can help determine which type you can receive and why.

Some thrombolytic medications doctors often prescribe include:

  • alteplase (Activase)
  • anistreplase (Eminase)
  • reteplase (Retavase)
  • streptokinase (Streptase)
  • tenecteplase (TNKase)
  • urokinase (Kinlytic)

Another drug — prourokinase — was effective in a 2023 clinical trial, but the Food and Drug Administration (FDA) hasn‘t approved it yet.

The main risk of thrombolytic therapy is internal bleeding, including brain bleeds. Kidney damage can also occur, especially in people with diabetes.

Other possible side effects include:

A healthcare professional may not recommend this treatment if you have a significant risk of heavy bleeding. Pregnant people and older adults may also be at greater risk of complications from this procedure.

Conditions that may prevent you from receiving thrombolytic therapy include:

  • severe kidney disease
  • history of brain bleeds or traumatic brain injury
  • a recent brain or spinal surgery

Thrombolysis is highly effective at removing blood clots, but it may not work for everyone. Some people can develop new blood clots even after thrombolysis.

Healthcare professionals typically recommend ongoing monitoring through tests, such as leg sonograms, to look for new clot formations. They may also recommend continued use of oral thrombolytics or other medications that reduce blood clot formation.

You can be your own best advocate by bringing the following blood clot symptoms to a healthcare professional’s attention immediately, should they occur:

  • sharp chest pain
  • shortness of breath
  • coughing up blood
  • discoloration or a feeling of warmth, cramping, throbbing, or swelling in an arm or leg

How do thrombolytics differ from anticoagulants?

People also call anticoagulants blood thinners. Unlike thrombolytics, they don’t treat existing clots. Instead, they stop clots from forming. They may also help stop existing clots from getting bigger.

Is thrombolysis the same as clot-busting?

Sometimes, people call thrombolytic drugs “clot busters” because they dissolve or break clots apart.

Can you have both thrombolysis and thrombectomy?

Yes, healthcare professionals may perform a thrombectomy as part of a thrombolysis procedure. You may receive clot-busting drugs through a catheter equipped with tools. Healthcare professionals can use these mechanical tools to cut up and remove a blood clot.

Thrombolytic therapy (thrombolysis) is the use of blood clot-dissolving medications. Healthcare professionals most commonly use it as an emergency treatment to stop or prevent damage from a heart attack, stroke, or pulmonary embolism.

The most common side effects of thrombolytics are bleeding or the blood clot traveling to another site in the body. Thrombolytics may not be appropriate for people at high risk of bleeding or who have a history of kidney disease.