• Suitable for the majority of patients
• Adjunctive heparin not needed
• Give streptokinase 1.5 MU as an IV infusion over 1 h

Alteplase (tissue plasminogen activator (tPA)): standard regimen

• Use if the patient has received streptokinase within the previous 4 days to 12 months
• Adjunctive heparin and antiplatelet therapy should be given
• Give alteplase 1.5 mg/kg as an IV infusion over 3 h
• Give heparin 5000 U IV bolus, followed by a continuous IV infusion to maintain APTT 1.5–2.5 times control (Chapter 103) for at least 2 days

Alteplase: accelerated regimen

• May be of additional benefit in patients aged <50 with large anterior infarcts presenting within 4 h who are normotensive (systolic BP <140 mmHg), that is, low risk of haemorrhagic stroke
• Adjunctive heparin and antiplatelet therapy should be given
• Give alteplase 15 mg IV bolus, followed by 0.75 mg/kg (maximum 50 mg) over 30 min, and followed by 0.5 mg/kg (maximum 35 mg) over the next 60 min
• Give heparin 5000 U IV bolus, followed by a continuous IV infusion to maintain APTT 1.5–2.5 times control (Chapter 103) for at least 2 days