What is the relationship between streptokinase and tenecteplase (tissue plasminogen activator) in terms of risk for intracranial hemorrhage?

Comparison of Streptokinase and Tenecteplase for Intracranial Hemorrhage Risk

Tenecteplase has a higher risk of intracranial hemorrhage compared to streptokinase, but offers better efficacy and practical advantages that may justify its use in appropriate clinical scenarios.

Risk Comparison Between Agents

Streptokinase

• Has the lowest rate of intracranial hemorrhage (ICH) among thrombolytic agents at approximately 0.37-0.51% 1
• Administration may cause hypotension and allergic reactions 1
• Re-administration should be avoided due to antibody formation and increased allergic reaction risk 1

Tenecteplase (TNK-tPA)

• Associated with higher ICH risk of approximately 0.94% 1
• Single-bolus weight-adjusted administration makes it more practical than alteplase 1
• Demonstrates greater fibrin specificity than alteplase 2

Risk Factors for Intracranial Hemorrhage

Both agents share common risk factors for intracranial hemorrhage:

• Advanced age (>65 years) - increases risk 2.2 times 3
• Lower weight (<70 kg) - increases risk 2.1 times 3
• Hypertension on admission - increases risk 2.0 times 3
• Female gender 1
• Prior cerebrovascular disease 1

Clinical Considerations

Absolute Contraindications for Both Agents 1

• Previous intracranial hemorrhage
• Ischemic stroke within 6 months
• Central nervous system damage, neoplasms, or AV malformation
• Recent major trauma/surgery/head injury (within 3 weeks)
• Gastrointestinal bleeding within past month
• Known bleeding disorder
• Aortic dissection
• Non-compressible punctures in past 24 hours

Management of Bleeding Complications

• Immediate discontinuation of thrombolytic infusion if active bleeding occurs 4
• Rapid assessment of bleeding severity, vital signs, and laboratory values 4
• For ICH: urgent neurosurgical consultation, blood pressure control (SBP <140-160 mmHg), and urgent CT scan 4
• Administration of cryoprecipitate, fresh frozen plasma, and platelet transfusion as needed 4

Recent Evidence and Recommendations

For Myocardial Infarction

• Tenecteplase is equivalent to accelerated alteplase for 30-day mortality 1
• Tenecteplase is associated with significantly lower rates of non-cerebral bleeding and less need for blood transfusion compared to alteplase 1
• Bolus administration of tenecteplase makes it more practical in pre-hospital settings 1

For Ischemic Stroke

• Recent evidence suggests tenecteplase may have lower mortality rates (8.2% vs 9.8%) and lower risk of major bleeding compared to alteplase 5
• The 0.25 mg/kg dose of tenecteplase appears to have better efficacy and safety profile than the 0.4 mg/kg dose 6
• Streptokinase is not recommended for stroke treatment due to unacceptably high rates of hemorrhage 1

Clinical Decision Algorithm

1. For myocardial infarction:

   • If pre-hospital administration is needed: Consider tenecteplase (single bolus administration)
   • If patient has history of streptokinase exposure: Use tenecteplase (avoid streptokinase re-administration)
   • If patient has high bleeding risk (elderly, low weight, female, hypertension): Consider streptokinase if no contraindications exist

2. For ischemic stroke:

   • Streptokinase should not be used (unacceptably high hemorrhage rates) 1
   • Tenecteplase may be considered as an alternative to alteplase, particularly at 0.25 mg/kg dose 1

Conclusion

While streptokinase has a lower risk of intracranial hemorrhage than tenecteplase, clinical decision-making must balance this advantage against tenecteplase's greater efficacy, practical single-bolus administration, and lower non-cerebral bleeding risk. For stroke treatment specifically, streptokinase should be avoided entirely, while tenecteplase shows promise as an alternative to alteplase.