How tPA Works for Stroke

Tissue plasminogen activator (tPA) is a drug given through a vein to help break up a blood clot so that blood flow can return to normal. It is used for the emergency treatment of ischemic stroke, which occurs when a blood clot interrupts blood flow to a region of the brain.

The timely administration of tPA can save lives. And because tPA restores blood flow by dissolving the clots in a blood vessel, it may limit the damage from a stroke and protect against quality of life impacts, like mobility loss or speech difficulties.

This article explains what tPA is and how it works to break down a clot. It discusses how healthcare providers make a decision about tPA administration, why it's not always possible to use the drug, and the side effects and complications that may arise from tPA use.

What tPA Does

A protein that naturally occurs in the body, tPA can be found on endothelial cells—the cells that line blood vessels.

It activates the conversion of plasminogen to plasmin, an enzyme responsible for the breakdown of clots. This helps restore blood flow that would otherwise remain impeded.

An experienced medical team can administer tPA in its powerful medication form when rapid clot-busting is needed.

Who Can Get tPA?

Prior to receiving treatment with tPA, you should expect your healthcare provider to review your medical history and order a brain computerized tomography (CT) scan. This is because there are several medical conditions that make it too dangerous for you to receive tPA.

If you have any of these conditions, not only would tPA not help you, it could cause significant harm to your health. You are ineligible to receive treatment if any of the following apply:

• Hemorrhagic stroke (bleeding in the brain)
  
• Brain aneurysm or AVM
• Previous intracranial hemorrhage
• Symptoms of a subarachnoid hemorrhage
• Recent history of surgical procedure
• Head injury/trauma
• History of stroke in the last three months
• Bleeding or blood clotting disorder
• Bleeding ulcer
• Pregnancy
• Use of blood-thinning medication
• Uncontrolled high blood pressure (above 185/110 mmHg)
• Low blood sugar (below 50 mg/dL)

Protocols have been established to rapidly identify whether you could be having a stroke, so that your testing and treatment can be prompt and efficient, allowing you to receive life-saving treatments in a timely manner.

In fact, some centers are making strides in diagnosing stroke sooner than ever before via mobile stroke units.

Timeframe for Administration

Treatment with tPA has been effective for people with an ischemic stroke as long as it is received intravenously within up to 4.5 hours of the onset of symptoms.

In contrast, endovascular treatment to remove the clot or deliver tPA at the site of the clot is considered for up to 24 hours after a stroke.

Side Effects of tPA

While tPA has been shown to be beneficial in the treatment of stroke, there are risks associated with tPA treatment—even for people who have been medically cleared to receive it.

It is a powerful blood thinner, and serious side effects may occur, including the following:

• Hemorrhage (bleeding) affecting the brain: Causes headaches, weakness, confusion, loss of consciousness, seizures
• Hemorrhage of the digestive system: Causes blood in the stool or stomach pain
• Severe blood loss: Causes lightheadedness, low blood pressure, loss of consciousness
• Minor bleeding in the gums or nose
• Blood in the urine

If you experience any of these side effects, you should immediately inform your medical team.

Getting Prompt tPA Treatment

The best way to maximize the chances of receiving the most effective treatment for a stroke is to get to the emergency room as soon as possible if you believe a stroke may be occurring.

Symptoms of a stroke include:

• Trouble understanding words or speaking
• Numbness of the arm, face, or leg
• Blurred or blackened vision in one or both eyes
• Double vision
• Sudden, severe headache
• Vomiting
• Dizziness
• Difficulty walking
• Loss of balance or coordination
• Weakness of the face, arm, or leg
• Droopy face or eyelid
• Confusion

Note that a person having a stroke may not notice when they are experiencing symptoms. You may recognize these signs in someone else before they do, or vice versa.

A Word From Verywell

The use of tPA medication to break up clots in blood vessels has offered benefits to thousands of people since its use was first approved, but it can't be used in all cases.

It's important to recognize the signs and symptoms of stroke to ensure treatment begins as quickly as possible.