Alteplase is the product of recombinant DNA technology and is chemically 
identical to endogenous tissue-type plasminogen activator: Plasminogen is 
converted to plasmin by alteplase, and fibrinolysis of blood thrombi is 
subsequently stimulated. Alteplase is now firmly established as a treatment of 
choice in the management of acute myocardial infarction. The efficacy of 
intravenous alteplase in the treatment of pulmonary thromboembolism has also 
been established and appears to be similar to that of streptokinase and 
urokinase in this indication and in arterial thrombotic occlusion. However, its 
use in this latter indication and in other vascular disorders has not been as 
extensively documented. Although trials demonstrating the efficacy of 
intravenous alteplase in patients with deep vein thrombosis and intra-arterial 
alteplase in patients with arterial thrombotic occlusion exist, reliable data on 
the efficacy of the fibrinolytic in ischaemic stroke and intracranial 
haemorrhage are scarce. Little clinical benefit is apparent in patients with 
unstable angina, although careful use may be warranted in those with definite 
pretreatment coronary thrombi. Of concern, there is a suggestion that general 
use of alteplase in patients with unstable angina may be associated with 
increased incidence of myocardial infarction. The incidence of major haemorrhage 
associated with alteplase therapy increases with increasing dose and appears to 
be similar to that seen with other fibrinolytic agents. Thus, further 
well-designed studies of the use of alteplase in ischaemic stroke and cerebral 
haemorrhage are required. However, a small subset of patients with unstable 
angina and definite pretreatment coronary thrombi may benefit from alteplase 
therapy. Further, preliminary data suggest efficacy in the therapy of deep vein 
thrombosis and arterial thrombotic occlusion, and alteplase has a proven place 
in the fibrinolytic treatment of pulmonary thromboembolism.