It is supplied in 50 and 100 mg vials reconstituted with sterile water for injection to 50 and 100 mL respectively, giving a dose of 1 mg per mL. Each mg of alteplase has an activity of 580,000 IU (WHO).
The dose is determined by the patient's body weight. The maximum dose is 100 mg. It should be given within 4 hours after the myocardial infarction.
Administration is in 4 phases for the adult >= 65 kg:
(1) 10 mg is administered as an intravenous bolus over 1 minute.
(2) 50 mg is infused over the first hour.
(3) 20 mg is infused over the second hour
(4) 20 mg is infused over the third hour
For the adult weighing < 65 kg a total dose of 1.25 mg/kg is infused over 3 hours. To match the larger adult, this could be achieved as:
(1) 0.75 mg/kg is administered in the first hour, of which 6 mg can be administered as an intravenous bolus
(2) 0.25 mg/kg is infused in the second hour
(3) 0.25 mg/kg is infused in the third hour
