What is the recommended dosage and administration of tenecteplase (tnk-tPA) for the treatment of ST-Elevation Myocardial Infarction (STEMI)?

Tenecteplase Dosage and Administration for STEMI

Tenecteplase (TNK-tPA) should be administered as a single intravenous weight-based bolus over 5 seconds for patients with ST-Elevation Myocardial Infarction (STEMI). 1, 2

Recommended Dosage

The weight-based dosing for tenecteplase is as follows:

• <60 kg: 30 mg (6 mL) 1, 2
• 60-69 kg: 35 mg (7 mL) 1, 2
• 70-79 kg: 40 mg (8 mL) 1, 2
• 80-89 kg: 45 mg (9 mL) 1, 2
• ≥90 kg: 50 mg (10 mL) 1, 2

Timing of Administration

• Initiate treatment as soon as possible after the onset of STEMI symptoms 2
• Fibrinolysis with tenecteplase is recommended when primary PCI cannot be performed within 120 minutes of first medical contact 1
• Pre-hospital administration is preferred when feasible to minimize time to treatment 1
• Benefits are most significant within the first 12 hours after symptom onset, with greatest benefit in those presenting early 1

Preparation and Administration

1. Aseptically withdraw 10 mL of Sterile Water for Injection from the supplied diluent vial 2
2. Reconstitute the tenecteplase vial with the 10 mL of Sterile Water for Injection to obtain a final concentration of 5 mg/mL 2
3. Gently swirl until contents are completely dissolved (DO NOT SHAKE) 2
4. Withdraw the appropriate dose based on patient weight 2
5. Administer as a single intravenous bolus over 5 seconds 2

Important Considerations

Contraindications

Absolute contraindications include:

• Any prior intracranial hemorrhage 1
• Known structural cerebral vascular lesion 1
• Known malignant intracranial neoplasm 1
• Ischemic stroke within 3 months (except acute ischemic stroke within 4.5 hours) 1
• Suspected aortic dissection 1
• Active bleeding or bleeding diathesis 1
• Significant closed-head or facial trauma within 3 months 1
• Intracranial or intraspinal surgery within 2 months 1
• Severe uncontrolled hypertension (SBP >180 mm Hg or DBP >110 mm Hg) 1

Adjunctive Therapy

• Aspirin: Administer oral or IV aspirin to all patients 1
• Clopidogrel: Add to aspirin therapy 1
• Anticoagulation: Recommended until revascularization or hospital discharge (up to 8 days) 1
  • Enoxaparin IV followed by subcutaneous (preferred over UFH) 1
  • Unfractionated heparin (UFH): Weight-adjusted IV bolus followed by infusion 1

Post-Fibrinolytic Management

• Transfer to a PCI-capable center following fibrinolysis is indicated in all patients 1
• Angiography and PCI of the infarct-related artery is recommended between 2-24 hours after successful fibrinolysis 1
• Emergency angiography and PCI is indicated if fibrinolysis fails (<50% ST-segment resolution at 60-90 minutes) 1

Clinical Efficacy and Safety

• Tenecteplase has equivalent 30-day mortality outcomes compared to alteplase 3
• Tenecteplase is associated with fewer non-cerebral bleeding complications compared to alteplase 3
• The single-bolus administration of tenecteplase facilitates more rapid treatment both in and out of hospital settings 3
• Clinical success rates are highest (>96%) when administered within 3 hours of symptom onset 4

Special Populations

• Elderly patients (>70 years) have lower clinical success rates (92.11%) and higher mortality (4.42%) 4
• Delayed treatment (>6 hours after symptom onset) is associated with significantly lower success rates (85.38%) and higher mortality (4.98%) 4

Chemical Incompatibilities

• Tenecteplase is incompatible with dextrose-containing solutions 2
• Flush dextrose-containing lines with 0.9% sodium chloride solution before and after administration 2

Tenecteplase's single-bolus administration offers significant advantages over other fibrinolytic agents, particularly in pre-hospital settings where rapid administration is crucial for improving outcomes in STEMI patients 1, 3.