What is the correct Alteplase dosing regimen?

• A. 50 mg IV bolus
• B. 15 mg IV bolus then 0.75 mg/kg infusion
• C. 15 mg IV bolus only
• D. 100 mg IV bolus

Answer: (B)

Alteplase in acute ST-elevation scenarios is given as a two-step regimen: a fixed initial IV bolus of 15 mg, followed by a weight-based IV infusion of 0.75 mg/kg. This approach starts rapid clot dissolution with the bolus and then sustains thrombolysis through the infusion, balancing effectiveness with bleeding risk. The dose is tailored by weight to ensure the thrombolytic exposure is appropriate for the patient, and total dosing guidelines cap the amount to stay within safe limits. The other patterns—a single large bolus, a wrong total dose, or a bolus without infusion—do not provide the established balance of rapid and sustained thrombolysis.