Clinical experience with thrombolytics in non-coronary disorders is limited to 
the plasminogen activators streptokinase, urokinase and alteplase; therapeutic 
trials with anistreplase (APSAC) are almost, and with saruplase completely, 
limited to acute myocardial infarction. In terms of thrombus clearance, 
thrombolytic drugs are superior to heparin in patients with recent deep vein 
thrombosis in the pelvis or lower limbs. In aggregate, thrombi younger than 8 
days are lysed in approximately 60% of patients treated with streptokinase, 
urokinase or alteplase. The results of studies assessing the subsequent 
development of the postphlebitic syndrome are conflicting, but most suggest that 
thrombolytic therapy can reduce symptoms of chronic venous insufficiency. 
Currently, the combination of systemic thrombolytic drugs followed by heparin is 
recommended for patients with acute major pulmonary embolism who are 
haemodynamically unstable. Streptokinase, urokinase and alteplase have all been 
shown to accelerate the lysis of pulmonary emboli and to decrease pulmonary 
vascular obstruction and pulmonary hypertension. Systemic venous or 
intrapulmonary infusions of alteplase offers the same benefit in terms of 
angiographic and haemodynamic improvement. A short infusion of 100 mg alteplase 
over 2 hours seems to be superior to a 24-hour infusion of urokinase. None of 
the thrombolytic trials in pulmonary embolism have been large enough to 
demonstrate a reduction in mortality. It is now generally accepted that, unless 
contraindicated, thrombolytic therapy is the front-line treatment for patients 
with massive pulmonary embolism and major haemodynamic disturbance. The local 
treatment of acute arterial occlusion in limb arteries results in rapid clearing 
of the artery in 67% of patients treated with streptokinase; the corresponding 
success rates for urokinase and alteplase are 81% and 88 to 94%, respectively. 
The main question appears to be the identification of patients in whom local 
thrombolysis is the treatment of choice, as opposed to established therapeutic 
modalities. Thrombolytic treatment following a major ischaemic stroke is 
hazardous, although clinical improvement has been noted in a minority of 
patients with recanalised cerebral arteries. The safety and efficacy of 
thrombolytic treatment remains unproven for this indication, and its use must be 
restricted to experimental protocols. Thrombolytic treatment in retinal artery 
or vein occlusion has, in practice, been abandoned.