TPA: Tissue Plasminogen Activator for Stroke

Tissue plasminogen activator, most commonly known as TPA, is a powerful blood thinner used for emergency stroke treatment. Activase (alteplase) is a biosynthetic form of this drug.

Approved by the Food and Drug Administration (FDA) in 1996 for the treatment of stroke, it was initially viewed as both revolutionary and risky. Since then, stroke treatment has advanced a lot, but TPA is still the most dramatic improvement to come about in the care of stroke patients.

This article will provide information about TPA for emergency stroke treatment.

Doctors and nurse pulling hospital trolley — Clerkenwell / Getty Images

What Is TPA and Why Is It Used for Strokes?

Tissue plasminogen activator is a powerful agent that dissolves blood clots. It is injected by intravenous administration (IV) for emergency stroke treatment.

A stroke is caused by an interruption in blood flow either due to a blood clot (ischemic stroke) or a bleed (hemorrhagic stroke) in the brain. TPA is only used for strokes caused by blood clots.

When TPA is injected into a vein, it quickly travels through the blood to reach the clogged blood vessel, where it works by trying to dissolve the blood clot and to restore blood flow to the brain. This allows the brain to remain healthy before stroke damage can occur.

Tenecteplase (TNK) is a genetically-modified form of human TPA that is now also in use. It does not need to be weight-based.

Can You Ask for TPA?

Intravenous TPA has to be administered within the first few hours after a stroke begins. The start of a stroke is counted from the time the person is last seen well (also known as "last known well") and not displaying or experiencing stroke signs or symptoms.

After this very short window of a few hours after a stroke starts, you cannot receive TPA because it might cause more harm than good at that point.

Clinical Guidelines for the Use of TPA

Clinical guidelines for the early treatment of stroke published jointly by the American Heart Association and American Stroke Association strongly recommend the use of TPA for eligible patients within 4.5 hours of symptom onset. Some of the eligibility criteria involved in the decision to use TPA include other heart conditions, blood glucose levels, blood pressure levels, and age.

Most of the time, patients do not ask for TPA. But emergency medical workers are trained to recognize a stroke and emergency rooms are equipped with the staff and provisions to administer TPA when it is necessary.

Does TPA Help Strokes?

Since its inception, TPA has been administered to many patients. The long-term and short-term effects of TPA have been carefully evaluated. Overall, in the right circumstances, TPA has been proven to be beneficial.

A comparison of stroke patients who did receive TPA vs. stroke patients who did not receive TPA showed that the group of patients who were treated with TPA experienced better physical function, better cognitive abilities, and better survival rates than the stroke patients who did not get the TPA treatment.

The sooner stroke patients receive TPA, the better the recovery. For every 15-minute delay in TPA treatment, the poorer the outcome. In fact, a national quality improvement initiative aimed at reducing the waiting time for TPA administration improved patients’ survival and decreased complications of TPA treatment.

Mobile stroke units in some cities can help stroke patients receive treatment faster.

Complications of TPA

Because TPA is a powerful blood thinner, the main side effect is bleeding. Bleeding is a serious complication that can result in a hemorrhagic stroke, which is often more serious than an ischemic stroke.

Additionally, TPA can cause stomach bleeding, intestinal bleeding, bleeding in the urine, or bleeding of healing wounds or surgical incisions. For these reasons, some patients are not candidates for TPA.

TPA is very fast acting, and its effect does not last very long. If you receive TPA and do not experience any side effects or complications within the first few days, you do not need to be concerned about delayed or long-term side effects from TPA during your recovery or after you go home.

A Word From Verywell

TPA is an important stroke treatment that can save your life. However, it can be dangerous and not everyone is a safe candidate for TPA. Also, if the narrow window of time to safely use TPA has elapsed by the time you reach the hospital, you cannot receive intravenous TPA treatment. It is only beneficial if it is given within the first few hours after a stroke has started.

6 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Li S, Pan Y, Wang Z, et al. Safety and efficacy of tenecteplase versus alteplase in patients with acute ischaemic stroke (TRACE): a multicentre, randomised, open label, blinded-endpoint (PROBE) controlled phase II study. Stroke Vasc Neurol. 2022;7(1):47-53. doi:10.1136/svn-2021-000978
Powers WJ, Rabinstein AA, Ackerson T, et al. Guidelines for the early management of patients with acute ischemic stroke: 2019 update to the 2018 guidelines for the early management of patients with acute ischemic stroke: a guideline for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2019;50(12). doi:10.1161/STR.0000000000000211
Tsivgoulis G, Safouris A, Alexandrov AV. Safety of intravenous thrombolysis for acute ischemic stroke in specific conditions. Expert Opin Drug Saf. 2015;14(6):845-864. doi:10.1517/14740338.2015.1032242
Lang CE, Bland MD, Cheng N, Corbetta M, Lee JM. A case-control study of the effectiveness of tissue plasminogen activator on 6 month patients--reported outcomes and health care utilization. J Stroke Cerebrovasc Dis. 2014;23(10):2914-2919. doi:10.1016/j.jstrokecerebrovasdis.2014.07.049
Saver JL, Fonarow GC, Smith EE, et al. Time to treatment with intravenous tissue plasminogen activator and outcome from acute ischemic stroke. JAMA. 2013;309(23):2480-2488. doi:10.1001/jama.2013.6959
Fonarow GC, Zhao X, Smith EE, et al. Door-to-needle times for tissue plasminogen activator administration and clinical outcomes in acute ischemic stroke before and after a quality improvement initiative. JAMA. 2014;311(16):1632-1640. doi:10.1001/jama.2014.3203

By Heidi Moawad, MD
Dr. Moawad is a neurologist and expert in brain health. She regularly writes and edits health content for medical books and publications.

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