Recommended Dosage of Tenecteplase (TNK) for STEMI
The recommended dose of tenecteplase (TNK) for STEMI is weight-based: 30 mg for patients <60 kg, 35 mg for 60-69 kg, 40 mg for 70-79 kg, 45 mg for 80-89 kg, and 50 mg for ≥90 kg, administered as a single intravenous bolus over 5 seconds. 1, 2
Dosing Guidelines and Administration
The FDA-approved dosing of tenecteplase for STEMI follows a weight-based protocol:
| Patient Weight (kg) | TNKase (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 |
Administration should be performed as follows:
- Administer as a single IV bolus over 5 seconds
- Initiate treatment as soon as possible after symptom onset
- Reconstitute with 10 mL Sterile Water for Injection to obtain a final concentration of 5 mg/mL
- Flush dextrose-containing IV lines with 0.9% sodium chloride before and after administration 2
Special Populations
Elderly Patients
- For patients >75 years old, consider half-dosing to reduce the risk of intracranial hemorrhage 1
- This recommendation is based on the STREAM trial, which showed that a 50% reduction in tenecteplase dose in elderly patients was associated with a significant reduction in stroke rates 1
Obese Patients
- For patients with Class 3 obesity (BMI ≥40), the standard weight-based dosing should be used with a ceiling dose of 50 mg 1
- Appropriate measurement of body weight is important to avoid underdosing 1
Clinical Context and Evidence
Tenecteplase is a genetically engineered version of alteplase with:
- 15-fold higher fibrin specificity
- 80-fold reduced binding affinity to PAI-1
- 6-fold prolonged plasma half-life (22 minutes vs 3.5 minutes) 3
These properties allow tenecteplase to be administered as a single bolus rather than requiring a 90-minute infusion like alteplase. According to the 2025 ACC/AHA guidelines, tenecteplase is preferred over non-fibrin-specific agents due to superior patency rates and less immunogenicity 1.
In a large randomized trial, tenecteplase and alteplase showed equivalent 30-day mortality rates, but tenecteplase was associated with reduced non-cerebral bleeding 1.
Contraindications
Absolute contraindications to tenecteplase include:
- Any prior intracranial hemorrhage
- Known structural cerebral vascular lesion
- Known malignant intracranial neoplasm
- Ischemic stroke within 3 months
- Suspected aortic dissection
- Active bleeding or bleeding diathesis
- Significant closed-head or facial trauma within 3 months
- Intracranial or intraspinal surgery within 2 months
- Severe uncontrolled hypertension 1, 2
Adjunctive Therapy
When administering tenecteplase for STEMI:
- Give oral aspirin (150-325 mg) or IV aspirin (250-500 mg) if oral ingestion is not possible
- Add clopidogrel (300 mg loading dose if ≤75 years; 75 mg if >75 years)
- Provide anticoagulation until revascularization or for the duration of hospital stay (up to 8 days)
- Enoxaparin IV followed by SC (preferred over UFH) or weight-adjusted UFH 1
Clinical Pitfalls to Avoid
Delayed administration: Initiate tenecteplase as soon as possible after STEMI diagnosis, as efficacy is time-dependent with greatest benefit within the first 12 hours after symptom onset 1
Incorrect dosing in elderly: Failure to reduce the dose in patients >75 years increases the risk of intracranial hemorrhage 1
Administration with dextrose solutions: Tenecteplase is incompatible with dextrose-containing solutions and may precipitate. Always flush lines with 0.9% sodium chloride before and after administration 2
Ignoring contraindications: Carefully screen for absolute and relative contraindications before administering tenecteplase to minimize bleeding risks 1
Inadequate post-fibrinolysis care: Transfer patients to a PCI-capable center immediately after fibrinolysis for potential rescue PCI if needed 1
The weight-based dosing of tenecteplase provides an effective balance of efficacy and safety in STEMI treatment, with the convenience of single-bolus administration making it particularly suitable for pre-hospital or early in-hospital use.