For years, a medication called tPA (tissue plasminogen activator) has been used by doctors to help dissolve stroke-causing blood clots. This medication is developed from a molecule already naturally produced by your body. When you are having a stroke, your body can’t produce this molecule fast enough. Administering tPA in the first few hours after a stroke can break up clots and improve your chances of returning to normal.
Now, more hospitals and health systems (including Henry Ford Health) are making the switch to a different medication called TNK (tenecteplase) to help stop stroke. Christopher Lewandowski, M.D., an emergency medicine doctor at Henry Ford Health, explains how this new medication can improve stroke outcomes for patients.
TNK vs. tPA
“TNK is a modification of tPA,” says Dr. Lewandowski. “It is just as safe and effective to use and makes it easier for emergency care teams to treat stroke.”
When tPA is used, it is administered in two doses. The first can be administered quickly, while the second dose requires a one-hour IV infusion. This means that patients often have to wait until they receive this medication before they can be transferred to a different department of the hospital for additional care. TNK is administered in a single injection. Instead of having to wait for an IV drip like with tPA, TNK can be given quickly (in less than five seconds). This means patients can be transferred for additional care much quicker.
“Both these medications were developed to break down blood clots, however TNK is more effective at dissolving clots and may work better on larger clots,” says Dr. Lewandowski. “TNK can dissolve blood clots without surgery in about 20% of cases while tPA can only dissolve clots in about 10% of large clot cases.”
How Doctors Treat Stroke
Henry Ford Stroke Care
If someone is experiencing symptoms of stroke, call 911 immediately. Once medical professionals arrive, they will take the patient to the closest stroke center. Tests (like a CT scan) will be used to evaluate brain health before stroke-stopping medication is administered in the emergency room.
“Regardless of if an ER is using tPA or TNK, this medication needs to be administered through a vein within four and a half hours of someone having a stroke,” says Dr. Lewandowski. “Stroke needs to be treated immediately, and, for patients with clots in a large blood vessel of the brain, your best chances for recovery mean that you are getting in for surgery as soon as possible but within 24 hours of initial stroke symptoms.”
If surgery is necessary, doctors will perform an operation called a thrombectomy. In this procedure, the surgeon will remove the clot that is causing the stroke by pulling it out through an artery.
As of now, TNK is not FDA-approved for stroke care (though it is for heart attacks), but the National Institute of Neurological Disorders and Stroke and the American Heart Association both highlight that it is effective and safe for stroke use.
Reviewed by Dr. Christopher Lewandowski, an emergency medicine doctor at Henry Ford Health.
