What is the recommended dose of tenecteplase (tissue plasminogen activator) for pulmonary embolism?

Recommended Dosing of Tenecteplase for Pulmonary Embolism

For pulmonary embolism, tenecteplase should be administered as a single weight-based intravenous bolus: 30 mg for weight <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. 1

Indications for Thrombolytic Therapy in PE

Thrombolytic therapy with tenecteplase is primarily indicated in specific clinical scenarios:

1. Massive PE with hemodynamic instability - Patients with confirmed PE who present with:

   • Persistent hypotension (systolic BP <90 mmHg)
   • Cardiogenic shock
   • Cardiac arrest 1

2. Selected cases of submassive PE - Patients with right ventricular dysfunction but normal blood pressure who have:

   • Low bleeding risk
   • High risk of clinical deterioration 1, 2

Administration Protocol

• Administer tenecteplase as a single IV bolus according to weight-based dosing
• No need for prolonged infusion (unlike alteplase which requires 90-minute infusion)
• Anticoagulation with heparin should be temporarily suspended during administration
• Restart heparin after 3 hours when aPTT is less than twice the upper limit of normal 3

Contraindications

Absolute Contraindications:

• 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

Relative Contraindications:

• History of chronic, severe, poorly controlled hypertension
• Significant hypertension on presentation
• History of prior ischemic stroke >3 months
• Dementia
• Major surgery (<3 weeks)
• Recent internal bleeding
• Noncompressible vascular punctures
• Pregnancy
• Active peptic ulcer
• Oral anticoagulant therapy 1

Monitoring and Follow-up

• Monitor vital signs, oxygen saturation, and hemodynamic parameters continuously
• Assess for bleeding complications (particularly intracranial hemorrhage)
• Evaluate improvement in right ventricular function via echocardiography
• Monitor platelet counts during subsequent heparin therapy 3

Clinical Evidence Supporting Tenecteplase Use

Multiple studies have demonstrated the efficacy of tenecteplase in PE:

• Tenecteplase has shown significant reduction in right ventricular systolic pressure and improvement in right ventricular dysfunction 4, 5
• Treatment with tenecteplase is associated with increased probability of favorable outcomes in submassive PE 2
• Tenecteplase administration results in significant improvement in oxygen saturation compared to other thrombolytics 6

Advantages of Tenecteplase

• Single bolus administration (more convenient than alteplase's 90-minute infusion)
• Higher fibrin specificity
• Reduced risk of non-cerebral bleeding compared to other thrombolytics 1
• Particularly beneficial in emergency settings where rapid administration is critical 1

Special Considerations

• In elderly patients (>75 years), consider a 50% reduction in tenecteplase dose to reduce stroke risk 1
• For patients in cardiac arrest with confirmed or suspected PE, thrombolysis can be beneficial even when chest compressions have been provided 1
• Transfer patients to PCI-capable centers immediately after thrombolytic therapy when possible 1

Remember that while tenecteplase offers advantages in terms of administration convenience, patient selection remains critical to balance the benefits of rapid clot dissolution against the risks of bleeding complications.