Accelerated Alteplase Regimen for Acute Myocardial Infarction
No, the accelerated regimen of alteplase for acute myocardial infarction is NOT weight-based—it uses a fixed maximum dose of 100 mg regardless of patient weight, administered as 15 mg bolus followed by 50 mg over 30 minutes, then 35 mg over 60 minutes. 1
Dosing Protocol for Accelerated Alteplase
The accelerated alteplase regimen differs fundamentally from weight-based fibrinolytics:
- Total dose: Up to 100 mg maximum, given over 90 minutes 1
- Administration schedule:
- 15 mg IV bolus over 1-2 minutes
- 50 mg infusion over 30 minutes
- 35 mg infusion over 60 minutes 1
- No weight adjustment: The dose remains fixed at 100 mg total regardless of patient body weight 1, 2
Contrast with Weight-Based Fibrinolytics
This stands in stark contrast to newer agents that ARE weight-based:
- Tenecteplase (TNK-tPA): Single bolus, weight-adjusted from 30-50 mg based on body weight categories 1, 3
- Stroke dosing: Alteplase for stroke uses 0.9 mg/kg (maximum 90 mg), which IS weight-based 1
Clinical Rationale
The European Society of Cardiology established that the accelerated alteplase regimen with concomitant IV heparin results in 10 fewer deaths per 1000 patients treated compared to streptokinase, based on the landmark GUSTO trial 1. This fixed-dose regimen achieved higher plasma concentrations (3.2 ± 0.84 μg/ml) during the initial 30 minutes compared to standard 3-hour infusions, explaining the improved coronary patency rates 4.
Critical Dosing Distinction
Common pitfall: Confusing the AMI dosing with stroke dosing—alteplase for myocardial infarction uses a fixed 100 mg dose, while alteplase for stroke uses 0.9 mg/kg weight-based dosing 1. These are completely different protocols and must not be interchanged.
The pharmacokinetic profile shows alteplase has a predominant plasma half-life of only 3-5 minutes with terminal half-life of 72 minutes, cleared primarily by the liver 5, 4. This rapid clearance necessitates the continuous infusion approach rather than bolus dosing for AMI, unlike the weight-adjusted single-bolus tenecteplase 6.