Administration Protocol for Tenecteplase in Myocardial Infarction
Tenecteplase should be administered as a single intravenous bolus over 5 seconds with weight-adjusted dosing as follows: 30 mg if <60 kg, 35 mg if 60-<70 kg, 40 mg if 70-<80 kg, 45 mg if 80-<90 kg, and 50 mg if ≥90 kg. 1, 2
Timing and Indications
- Initiate treatment as soon as possible after the onset of STEMI symptoms to maximize benefits 1
- Tenecteplase is indicated to reduce mortality risk in acute ST-elevation myocardial infarction (STEMI) 1
- Treatment should be given within 12 hours of symptom onset; greatest benefit occurs with earlier administration 3
- Consider tenecteplase when primary PCI cannot be performed by an experienced team within 120 minutes of first medical contact 2
- For patients presenting very early (<2 hours after symptom onset) with a large infarct and low bleeding risk, fibrinolysis should be considered if time from first medical contact to balloon inflation is >90 minutes 2
Preparation and Administration
- Reconstitute the 50 mg vial with 10 mL of sterile water for injection to achieve a concentration of 5 mg/mL 1
- Gently swirl until completely dissolved; do not shake 1
- Determine appropriate dose based on patient's weight and withdraw this volume from reconstituted vial 1
- Inspect for particulate matter and discoloration before administration 1
- Flush dextrose-containing IV lines with 0.9% sodium chloride before and after administration to prevent precipitation 1
- Administer as a single IV bolus over 5 seconds 1
Weight-Based Dosing Table
| Patient Weight (kg) | Tenecteplase (mg) | Volume to be administered (mL) |
|---|---|---|
| < 60 | 30 | 6 |
| ≥ 60 to < 70 | 35 | 7 |
| ≥ 70 to < 80 | 40 | 8 |
| ≥ 80 to < 90 | 45 | 9 |
| ≥ 90 | 50 | 10 |
Adjunctive Therapy
- Aspirin: Administer oral loading dose of 150-300 mg or IV dose of 80-150 mg if oral ingestion not possible 2
- Clopidogrel: Indicated in addition to aspirin 2
- Anticoagulation: Required until revascularization (if performed) or for duration of hospital stay up to 8 days 2
- Preferred anticoagulant options:
- Enoxaparin: 30 mg IV bolus followed by 1.0 mg/kg subcutaneous injection every 12 hours (preferred over UFH in patients <75 years without significant renal dysfunction) 2
- Unfractionated heparin (UFH): 60 U/kg IV bolus (maximum 4000 U) followed by 12 U/kg/hour infusion (maximum 1000 U/hour), adjusted to maintain aPTT at 1.5-2.0 times control (approximately 50-70 seconds) 2
Post-Administration Monitoring
- Monitor ST-segment elevation, cardiac rhythm, and clinical symptoms over 60-180 minutes after initiation of therapy 2
- Signs of successful reperfusion include:
- Relief of symptoms
- Maintenance or restoration of hemodynamic and/or electrical stability
- Reduction of at least 50% of initial ST-segment elevation on follow-up ECG 60-90 minutes after initiation 2
- Monitor platelet counts daily in patients given UFH 2
- Transfer to a PCI-capable center following fibrinolysis is indicated in all patients 2
- Consider rescue PCI immediately if fibrinolysis has failed (<50% ST-segment resolution at 60 minutes) 2
Contraindications
- Active internal bleeding 1
- History of cerebrovascular accident 1
- Intracranial or intraspinal surgery or trauma within 2 months 1
- Intracranial neoplasm, arteriovenous malformation, or aneurysm 1
- Known bleeding diathesis 1
- Severe uncontrolled hypertension 1
Special Considerations
- In patients with known heparin-induced thrombocytopenia, consider bivalirudin as an alternative to heparin 2
- Avoid tenecteplase in patients >75 years when using LMWH as ancillary therapy 2
- Avoid LMWH in patients with significant renal dysfunction (serum creatinine >2.5 mg/dL in men or >2.0 mg/dL in women) 2
- Tenecteplase has a longer half-life (22 minutes vs 3.5 minutes) compared to alteplase, allowing for single bolus administration 4
- The combination of tenecteplase, aspirin, enoxaparin, and clopidogrel has been extensively studied as part of a pharmacoinvasive strategy 2