Alteplase, sold under the brand name Activase among others, is a biosynthetic form of human tissue-type plasminogen activator (t-PA).

[5][2][3] Similar to other thrombolytic drugs, alteplase is used to dissolve clots to restore tissue perfusion, but this can vary depending on the pathology.

[15][16] Systemic thrombolysis can quickly restore right ventricular function, heart rate, and blood pressure in patients with acute PE.

[17] However, standard doses of alteplase used in systemic thrombolysis may lead to massive bleeding, such as intracranial hemorrhage, particularly in older patients.

[20] Novel alternatives to treat catheter occlusion, such as tenecteplase, reteplase, and recombinant urokinase, offer the advantage of shorter dwell times than alteplase.

[7] Plasmin is a fibrinolytic enzyme that cleaves the cross-links between polymerized fibrin molecules, causing the blood clot to break down and dissolve, a process called fibrinolysis.

[24][25] In May 1987, the United States FDA requested additional data for the drug rather than approve it outright, causing Genentech stock prices to fall by nearly one quarter.

The decision was described as a surprise to the company as well as many cardiologists and regulators,[26] and it generated significant criticism of the FDA, including from The Wall Street Journal editorial board.

[27][28] After results from two additional trials were obtained,[27] Alteplase was approved for medical use in the United States in November 1987 for the treatment of myocardial infarction.

[5][2][29][30] This was just seven years after the first efforts were made to produce recombinant t-PA, making it one of the fastest drug developments in history.

[35] There is a sex difference in the use of intravenous tissue plasminogen activator, as it is less likely to be used for women with acute ischemic stroke than men.