Tissue plasminogen activator (tPA) is an intravenous medicine
given for ischemic stroke
– a stroke caused by a blood clot – that can dissolve the stroke-causing clot. Studies show that people who receive tPA within 3 hours – up to 4.5 hours in some patients – have better and more complete recoveries.
When should tPA be administered?
IV tPA should be administered to all eligible acute stroke patients
within 3 hours of last known normal
and to a more selective group of eligible acute stroke patients (based on ECASS III exclusion criteria) within 4.5 hours of last known normal.
Why do you give tPA?
When administered quickly after stroke onset (within three hours, as approved by the FDA), tPA
helps to restore blood flow to brain regions affected by a stroke
, thereby limiting the risk of damage and functional impairment.
What is the indication for tPA?
FDA-approved indications for alteplase include
pulmonary embolism, myocardial infarction with ST-segment elevation (STEMI)
, ischemic stroke when given within 3 hours of the start of symptoms, and re-establishment of patency in occluded intravenous (IV) catheters.
When should iv tPA be given?
Alteplase (IV r-tPA)
within 4.5 hours of stroke onset
remains the standard of care for most ischemic stroke patients.
What happens if tPA is administered too slow?
Bolus
to infusion delays or interruptions in the infusion of TPA after the bolus may significantly impact serum TPA levels and may reduce the efficacy of thrombolysis.
Who is a good candidate for tPA?
Age older than 80 years
. Use of oral anticoagulants. Baseline NIH Stroke Scale score of greater than 25. History of both minor stroke and diabetes.
What are the major side effects of tPA?
The most common and serious side effect of alteplase is
bleeding
. Minor bleeding is more common, but significant bleeding such as into the brain (intracranial hemorrhage) or fatal bleeding also occurs. Other important side effects include: Nausea.
Why does tPA have to be given within 3 hours?
Now, research from the School of Medicine has cracked that window open a bit wider. If a patient arrives at the emergency room within three hours of experiencing stroke symptoms,
doctors can administer a potent clot-busting medication and often save critical brain tissue
.
What are the risks of tPA?
Complications related to intravenous r-tPA include
symptomatic intracranial hemorrhage, major systemic hemorrhage, and angioedema
in approximately 6%, 2%, and 5% of patients, respectively.
Why would you not give tPA?
There are strict protocols concerning the appropriate administration of tPA in patients with ischemic stroke, including a list of absolute and relative contraindications.
Because of the risk of hemorrhage is thought to outweigh any potential benefits
, patients with any absolute contraindication should not be given tPA.
What is the antidote for tPA?
They are used in clinical medicine to treat embolic or thrombotic stroke. The use of this protein is contraindicated in hemorrhagic stroke and head trauma. The antidote for tPA in case of toxicity is
aminocaproic acid
.
Why is tPA not given?
The drug tPA is able to bust up the clots to restore blood flow, thereby saving precious brain tissue. So why not give every stroke victim tPA? The reason is that
tPA is a powerful blood thinner
, and with that comes a risk of bleeding inside the brain.
What is the protocol for a stroke?
An IV injection of recombinant tissue plasminogen activator (tPA)
— also called alteplase (Activase) — is the gold standard treatment for ischemic stroke. An injection of tPA is usually given through a vein in the arm with the first three hours.
Is there an age limit for tPA?
Although
U.S. regulations have no age restrictions on use of r-tPA
, Europe (until recently) had restricted its use to patients younger than 80. Such discrepancies, and sparse safety data, may contribute to undertreatment of elderly patients with stroke-like symptoms.
Which type of stroke is most common?
Most strokes (87%) are
ischemic strokes
. An ischemic stroke happens when blood flow through the artery that supplies oxygen-rich blood to the brain becomes blocked. Blood clots often cause the blockages that lead to ischemic strokes.
