What are the contraindications for administering IV alteplase?
IV alteplase should not be administered to patients who have received a full treatment dose of LMWH within the previous 24 h, patients taking direct thrombin inhibitors or direct factor Xa inhibitors (unless laboratory tests such as aPTT, INR, platelet count, ecarin clotting time, thrombin time, or appropriate direct factor Xa activity assays are normal or the patient has not received a dose of these agents for >48 h), patients taking abciximab concurrently, patients taking IV aspirin within 90 min after the start of IV alteplase, patients with AIS and symptoms consistent with infective endocarditis, and patients with AIS known or suspected to be associated with aortic arch dissection.