Thrombolytic therapy: How best to use in acute MI

The choice of thrombolytic regimens can be a difficult one. Each agent has unique properties, and these must be understood before the correct choice can be made. Because of its bacterial origin, streptokinase may produce allergic reactions in a small percentage of patients; it is contraindicated in persons previously treated with it. Infarct-related patency rates of 60% to 70% have been reported with anistreplase, but this agent has not been shown to improve survival time when compared with other lytic drugs. Recombinant tissue plasminogen activator (rtPA) is fibrin-specific; its short half-life may permit vessel reocclusion, and concomitant heparin use is suggested. Reteplase, a good alternative, has a longer half-life and greater patency rates than rtPA, but survival rates are similar. Contraindications to thrombolytic therapy are conditions that put a patient at risk for bleeding and/or stroke.