The data reviewed above show that the ideal thrombolytic or thrombolytic plus anticoagulant regimen does not exist. Nor is it clear to me that one regimen is unequivocally better than another in regards to clinical outcome. Publication of the full results of the ISIS-3 study and completion of the TAPS study, the GUSTO study, the TIMI-4 study plus others only now in the planning phases, should help. This review will not stay current very long. These data do, however, give some guides to certain circumstances in which one regimen might be preferred over others. If economics is a compelling issue, as it may be in public hospitals on a fixed budget or in the developing world, streptokinase may be the best choice. For early application of thrombolytic therapy, such as at the site of infarct occurrence and in automotive and aerial ambulances, anistreplase may be preferred because of its ease of administration. Previous administration of streptokinase or anistreplase (within the period of 48 h to 6 months after prior use) militate against their use as does a recent streptococcal infection. Heightened concerns about bleeding risk, except intracranially, in the absence of absolute contraindication of fibrinolytic therapy, e.g. remote gastrointestinal hemorrhage or the expected imminent need for an invasive procedure, may lead to preference for alteplase over streptokinase or anistreplase. On the other hand, heightened concerns about intracranial hemorrhage may lead to preference for streptokinase over alteplase or anistreplase. Alteplase may be preferred over non-fibrin-selective agents in the treatment of patients when administration is begun more than three hours after the presumed onset of infarction. These considerations notwithstanding, it is crucial that debates over the best choice of a regimen must not be allowed to prolong the time before administration of an effective thrombolytic agent to a patient with evolving Q-wave infarction who is a good candidate for this therapy. This review may also become dated in the not-too-distant future because of expected further advances in thrombolytic regimen. Application of new antithrombotic regimens was noted above. Future thrombolytic and antithrombotic regimens may be "cocktails" of one or more thrombolytic agents plus more powerful antithrombotic and antiplatelet agents. New generations of thrombolytic agents may replace the current first and second generation agents now used. Combination thrombolytic and anti-fibrin antibody agents and mutant tissue-type plasminogen activators with lower affinity for plasminogen activator inhibitor and longer half-lives are being developed.(ABSTRACT TRUNCATED AT 400 WORDS)