Full Prescribing Information (PDF)
Dear Healthcare Provider Letter Triad Recall (PDF)

TNKase® (Tenecteplase) is a single-bolus thrombolytic, or clot-busting agent, approved by the U.S. Food and Drug Administration for use in mortality reduction associated with acute myocardial infarction (AMI). Treatment should be initiated as soon as possible after the onset of AMI symptoms.

TNKase is the first thrombolytic that can be administered over five seconds in a single dose, offering physicians the fastest administration of a thrombolytic to date in the treatment of heart attack. TNKase is a bioengineered variant of Activase® (Alteplase, recombinant), which is a recombinant DNA-derived version of naturally occurring tissue plasminogen activator (t-PA). It is constructed with amino acid substitutions at three sites (the letters T, N and K represent the three regions changed from the natural t-PA protein).

Status TNKase was approved for the treatment of acute myocardial infarction (AMI) in June 2000.

Important Safety Information

• TNKase therapy should not be used in the following conditions due to an increased risk of bleeding: active internal bleeding, history of stroke, brain or spinal surgery or a serious head injury within 2 months, brain tumor, an abnormal connection between veins and arteries, or abnormal bulge in the wall of an artery, problems with blood clotting, and severe uncontrolled high blood pressure.
• The most common side effect with TNKase therapy is bleeding. It can be internal bleeding, bleeding in the brain, bleeding from the digestive system, the urinary system, or the reproductive system, or the lungs. Bleeding can also happen from parts of the body where needles have been injected or parts of the body that have had recent surgery. Blood thinners may increase the risk of bleeding if taken before, during, or after TNKase therapy. Patients should inform their doctor of all prescription and over-the-counter drugs they are currently taking.
• A plug of cholesterol that blocks an artery (cholesterol embolism) has been reported rarely in patients treated with all types of clot dissolving agents. This is a serious condition which can be lethal, and is also associated with invasive medical procedures involving the arteries and veins.
• Irregular heart beats can also occur with TNKase therapy. In serious heart attack patients, doctors should choose either drug therapy that dissolves blood clots or a mechanical means to remove the clot as the main treatment strategy.

Please visit http://www.tnkase.com for the TNKase full prescribing information for additional important safety information.

Proposed Mechanism of Action TNKase works by stimulating the body's own clot-dissolving mechanism by activating plasminogen, a naturally occurring substance secreted by endothelial cells in response to injury to the artery walls that contributes to clot formation. When TNKase activates plasminogen, it converts into plasmin, which breaks down the fibrin mesh that binds the clot together. The clot is then dissolved, restoring blood flow to the heart.

Acute Myocardial Infarction Heart attack, or acute myocardial infarction, is caused when a blood clot obstructs a coronary artery supplying blood to the heart. This causes an inadequate flow of oxygenated and nutrient-enriched blood and results in the death of a portion of the heart muscle. Symptoms of a heart attack may include: uncomfortable pressure, fullness, squeezing or pain in the center of the chest that lasts for more than a few minutes; pain spreading to the shoulders, neck or arms; and chest discomfort with lightheadedness, fainting, sweating, nausea or shortness of breath. As many as 1.1 million Americans suffer heart attacks each year. Of these, about one-third will die, making heart attack the number one killer of men and women in the U.S. About 650,000 of these cases are first attacks while 450,000 are recurrent attacks.