Alteplase: descendancy in myocardial infarction, ascendancy in stroke

Tissue type plasminogen activator is available, through recombinant technol ogy, for thrombolytic use as alteplase. Alteplase is relatively clot specif ic and should cause less bleeding side effects than the non-specific agents such as streptokinase. Alteplase has been used successfully in evolving my ocardial infarction (MI) to reopen occluded coronary arteries. It is probab ly equally effective or superior to streptokinase in opening arteries and r educing mortality in Mi. Alteplase is most effective when given early in Mi and is probably ineffective when given 12 h after the onset of symptoms. T he effectiveness of alteplase in Mi can be increased by front loading with a bolus of 15 mg, followed by an infusion of 50 mg over 30 min and 35 mg ov er 60 min. Percutaneous transluminal coronary angioplasty or stenting is as sociated with a greater patency and lower rates of serious bleeding, recurr ent ischaemia and death than alteplase in MI and is likely to take over fro m alteplase as the standard Mi treatment. A reduced dose of alteplase to in crease coronary artery patency prior to angioplasty may be useful in Mi. An exciting new indication for the use of alteplase is in stroke, where it ha s become the first beneficial intervention. Alteplase is used to reopen occ luded cerebral vessels but is associated with an increased risk of intracer ebral haemorrhage. Alteplase is beneficial if given within 3 h of the onset of stroke but not after this time period. Therefore, the next challenge is to increase the percentage of people being diagnosed and treated within th is period. Clinical trials have not established a role for alteplase in the treatment of acute coronary syndromes or deep vein thrombosis. However, al teplase is useful in treating pulmonary thromboembolism and peripheral vasc ular disease.