What is a Tissue Plasminogen Activator?

A tissue plasminogen activator is an emergency medicine given to patients who have symptoms of active strokes or heart attacks. It works by dissolving blood clots and thinning the blood, which restores circulation to the brain and makes it easier for the heart to pump blood throughout the body. Doctors use extreme caution when providing intravenous tissue plasminogen activator drugs to avoid potentially fatal complications such as brain hemorrhages. When the medication is given at the first signs of a clotting-related condition, it is usually very effective at resolving problems before they cause permanent or life-threatening damage.

Blood vessels in the body naturally produce a type of tissue plasminogen activator protein that helps to resolve and prevent blood clots. In the case of a stroke or heart attack, however, there are not enough natural proteins to dissolve a major clot. Synthetic tissue plasminogen activator drugs provide a huge boost to the natural supply to immediately break up clots and restore blood flow.

A stroke occurs when the brain does not receive enough new oxygenated blood. Most cases are ischemic strokes, caused by blood clots in arteries in between the brain and the heart. It is also possible to have a hemorrhagic stroke that results from a broken, leaking blood vessel in the brain. The use of a tissue plasminogen activator is indicated only when doctors are certain that a patient is suffering an ischemic stroke. Since the blood is thinned, using the medication during a hemorrhagic stroke can actually worsen the problem since it increases the amount of blood lost through the broken vessel.

Before administering a tissue plasminogen activator, a physician carefully checks vital signs, reviews a patient's medical history, and takes a series of diagnostic brain scans. Computerized tomography scans are used to make sure symptoms are being caused by a ischemic stroke. If tests confirm blood clots, the drug can be given through a vein in the arm or leg. In the case of an advanced stroke that becomes life-threatening, a catheter may be used to inject the medication directly into the clotted artery.

Within the first three hours of having a heart attack, a patient may be given tissue plasminogen activators to reduce the chances of an impending stroke. Breaking up clots as soon as they start to appear helps to prevent brain involvement and limit the damage to heart muscle tissue. As with stroke victims, heart attack patients are thoroughly screened before receiving the drug to avoid dangerous complications.