Following intravenous bolus injection of 10 + 10 U in patients with acute myocardial infarction reteplase antigen is distributed in plasma with a dominant half-life (t1/ 2α) of 18±5 min and eliminated with a terminal half-life (t1/ 2ß) of 5.5 hours±12.5 min at a clearance rate of 121±25 ml/ min.