Alteplase (t-PA), a biosynthetic form of human tissue-type plasminogen activator (t-PA), is a thrombolytic medication, used to treat acute ischemic stroke, acute ST-elevation myocardial infarction (a type of heart attack), pulmonary embolism associated with low blood pressure, and blocked central venous catheter. It is given by injection into a vein or artery. Alteplase is the same as the normal human plasminogen activator produced in vascular endothelial cells and is synthesized via recombinant DNA technology in Chinese hamster ovary cells (CHO). Alteplase causes the breakdown of a clot by inducing fibrinolysis. It is on the World Health Organization's List of Essential Medicines. Medical uses Alteplase is mainly used to treat acute ischemic stroke, acute myocardial infarction, acute massive pulmonary embolism, and blocked catheters. Similar to other thrombolytic drugs, alteplase is used to dissolve clots to restore tissue perfusion, but this can vary depending on the pathology. Generally, alteplase is delivered intravenously into the body. To treat blocked catheters, alteplase is administered directly into the catheter. Alteplase has also been used off-label for deep vein thrombosis, peripheral artery disease, pleural effusion in children, prosthetic valve thrombosis, frostbite, and peritonitis. Ischemic stroke In adults diagnosed with acute ischemic stroke, thrombolytic treatment with alteplase is the standard of care during early management (within 4.5 hours of symptom onset). When mechanical thrombectomy is not available, alteplase may be considered up to 9 hours after symptom onset. Administration of alteplase is associated with improved functional outcomes and reduced incidence of disability. Alteplase used in conjunction with mechanical thrombectomy is associated with better outcomes. Use is restricted, however, if there is a risk of major bleeding or if there may be another cause of stroke symptoms. Alteplase is not recommended for those with non-disabling stroke. For patients with early recurrent ischemic stroke, repeated use of alteplase may be safe and efficacious. Alteplase is also commonly used in children, though guidelines are not yet standardized as they are for adults. Myocardial infarction Currently, the preferred treatment for ST-elevation myocardial infarction (STEMI) is percutaneous coronary intervention (PCI). However, PCI is only available at 25% of hospitals in the United States; alteplase is recommended if the patient is at a non-PCI capable hospital and cannot be transferred to receive PCI in under 120 minutes. Alteplase can also be used before arriving at the hospital if transportation time is anticipated to be greater than 30 minutes. Alteplase may be used in