What is the recommended dose of tenecteplase (tissue plasminogen activator) for myocardial infarction?

Tenecteplase Dosing for Myocardial Infarction

Administer tenecteplase as a single intravenous bolus using weight-based dosing: 30 mg for patients <60 kg, 35 mg for 60-<70 kg, 40 mg for 70-<80 kg, 45 mg for 80-<90 kg, and 50 mg for patients ≥90 kg, given over 5 seconds. 1, 2, 3, 4

Weight-Based Dosing Table

The following weight-adjusted dosing regimen is recommended by the European Society of Cardiology and FDA labeling 1, 2, 3, 4:

Patient Weight	Tenecteplase Dose	Volume (if using 50mg/10mL vial)
<60 kg	30 mg	6 mL
60 to <70 kg	35 mg	7 mL
70 to <80 kg	40 mg	8 mL
80 to <90 kg	45 mg	9 mL
≥90 kg	50 mg	10 mL

Administration Details

• Give tenecteplase as a single intravenous bolus over 5 seconds, not as an infusion 4
• The weight-based dosing (approximately 0.5 mg/kg) optimizes therapeutic efficacy while maintaining safety 5, 6
• Tenecteplase has a significantly longer half-life (22 minutes initial, 115 minutes terminal) compared to alteplase (3.5 minutes), which allows for single bolus administration 5, 6

Timing Considerations

• Initiate treatment as soon as possible after symptom onset, ideally within 12 hours of STEMI symptoms 1, 2, 4
• Greatest benefit occurs with earlier administration, particularly within the first 2 hours 1, 2
• Consider fibrinolysis when primary PCI cannot be performed by an experienced team within 120 minutes of first medical contact 1, 2
• For patients presenting very early (<2 hours) with large infarcts and low bleeding risk, use fibrinolysis if time from first medical contact to balloon inflation exceeds 90 minutes 1, 2

Mandatory Adjunctive Therapy

You must administer the following medications alongside tenecteplase 1, 2, 3:

Aspirin:

• Loading dose: 150-300 mg orally OR 80-150 mg IV if oral not possible 1, 2, 3
• Maintenance: 75-100 mg daily 1, 3

Clopidogrel:

• Loading dose: 600 mg orally (300 mg if age >75 years) 1, 3
• Maintenance: 75 mg daily 1, 3

Anticoagulation (required until revascularization or up to 8 days):

Preferred option - Enoxaparin: 1, 3

• Age <75 years: 30 mg IV bolus, then 1 mg/kg subcutaneous every 12 hours (maximum 100 mg for first two doses) 3
• Age ≥75 years: NO IV bolus; start with 0.75 mg/kg subcutaneous every 12 hours (maximum 75 mg for first two doses) 3
• Renal impairment (CrCl <30 mL/min): Give subcutaneous doses once every 24 hours regardless of age 3
• Critical caveat: Avoid enoxaparin in patients >75 years when possible due to increased intracranial hemorrhage risk (2.20% vs 0.97% with UFH) 7

Alternative - Unfractionated Heparin: 1, 3

• 60 U/kg IV bolus (maximum 4000 U) followed by 12 U/kg/hour infusion (maximum 1000 U/hour) for 24-48 hours 3
• Target aPTT: 50-70 seconds or 1.5-2.0 times control, monitored at 3,6,12, and 24 hours 3

Post-Administration Monitoring and Management

• Monitor ST-segment elevation, cardiac rhythm, and clinical symptoms over 60-180 minutes after administration 2, 3
• Successful reperfusion is indicated by: relief of symptoms, hemodynamic/electrical stability, and ≥50% reduction of initial ST-segment elevation on follow-up ECG at 60-90 minutes 2, 3
• All patients must be transferred to a PCI-capable center following fibrinolysis 1, 2, 3
• Perform rescue PCI immediately if fibrinolysis fails (<50% ST-segment resolution at 60 minutes) 1, 2, 3
• For stable patients after successful fibrinolysis, perform routine angiography with view to revascularization at 3-24 hours 1, 3

Absolute Contraindications

Do not administer tenecteplase if any of the following are present 4:

• Active internal bleeding
• History of cerebrovascular accident
• Intracranial or intraspinal surgery or trauma within 2 months
• Intracranial neoplasm, arteriovenous malformation, or aneurysm
• Known bleeding diathesis
• Severe uncontrolled hypertension

Common Pitfalls to Avoid

• Do not use enoxaparin in patients >75 years - the ASSENT-3 PLUS trial showed significantly increased intracranial hemorrhage (2.20% vs 0.97%) in elderly patients receiving enoxaparin with tenecteplase 7
• Do not use enoxaparin with significant renal dysfunction (serum creatinine >2.5 mg/dL in men or >2.0 mg/dL in women) 2
• Do not give tenecteplase as an infusion - it must be administered as a single bolus over 5 seconds 4
• Do not fail to transfer patients to PCI-capable centers after fibrinolysis, even if reperfusion appears successful 1, 2, 3
• Do not administer outside the 12-hour window except in specific circumstances (large area of myocardium at risk, hemodynamic instability, ongoing ischemia) when PCI is unavailable 8