Alteplase Administration Protocol for Massive Pulmonary Embolism
Direct Answer
No, do not give 10% of the total dose first as a bolus for massive pulmonary embolism—the FDA-approved regimen is 100 mg administered as a continuous intravenous infusion over 2 hours without an initial bolus. 1
Critical Distinction: Stroke vs. Pulmonary Embolism Protocols
The 10% bolus protocol you're referencing is exclusively for acute ischemic stroke, not pulmonary embolism:
- For stroke: Administer 0.9 mg/kg (maximum 90 mg) over 60 minutes, with 10% given as a bolus over 1 minute 2
- For massive PE: Administer 100 mg as a continuous infusion over 2 hours with no initial bolus 1
This is a common and dangerous pitfall—confusing stroke and PE protocols can lead to inappropriate dosing.
Recommended Dosing for Massive PE
Standard regimen for hemodynamically unstable patients:
- 100 mg alteplase administered as continuous IV infusion over 2 hours 1
- Administer via peripheral IV catheter 1
- Withhold heparin anticoagulation during the 2-hour infusion 1
- Resume anticoagulation after completion of alteplase 1
Alternative regimens based on clinical severity:
For cardiac arrest or rapidly deteriorating condition due to massive PE:
- 50 mg alteplase as IV bolus 1
For hemodynamically stable patients with confirmed massive PE:
- 100 mg over 90 minutes (accelerated MI regimen) 1
Evidence Supporting the 2-Hour Infusion
The continuous infusion approach is supported by multiple lines of evidence:
- The 100 mg/2-hour regimen has been directly compared to other thrombolytics and shown equivalent or superior efficacy 3
- Studies using reduced-dose bolus regimens (0.6 mg/kg over 15 minutes) showed efficacy but did not demonstrate superiority over the standard 2-hour infusion 4, 5
- The 2-hour infusion provides sustained thrombolytic effect with acceptable bleeding risk (10-40% minor bleeding complications) 1
Pediatric Considerations
If treating pediatric patients, different protocols apply:
- 0.1-0.6 mg/kg/hour IV for 6 hours, OR 2
- 0.2 mg/kg IV bolus (maximum 15 mg), then 0.75 mg/kg over 30 minutes (maximum 50 mg), followed by 0.5 mg/kg over 60 minutes (maximum 35 mg), with maximum total dose 100 mg 2
Clinical Decision Algorithm
Step 1: Confirm massive PE
- Sustained hypotension, shock index >1.0, or respiratory failure 1
- Imaging confirmation preferred, but may proceed with high clinical suspicion and RV dysfunction on bedside echo if patient too unstable for imaging 1
Step 2: Assess contraindications
- Absolute: Active bleeding, recent stroke, current GI hemorrhage 2
- Relative: Recent surgery (within 7 days), peptic ulcer disease, prolonged CPR 2
- In life-threatening PE, contraindications may need reconsideration given high mortality without treatment 1
Step 3: Select appropriate regimen
- Hemodynamically unstable but not arresting: 100 mg over 2 hours 1
- Cardiac arrest/extreme instability: 50 mg bolus 1
Step 4: Anticoagulation management