What is the recommended dosage of streptokinase for thrombolysis?

Streptokinase Dosing for Thrombolysis

The standard recommended dosage of streptokinase for thrombolysis is a loading dose of 250,000 IU administered over 30 minutes, followed by a maintenance infusion of 100,000 IU/hour for 12-24 hours. 1

Indications and Administration

Streptokinase is primarily indicated for thrombolysis in:

• Pulmonary embolism (PE): Particularly for acute massive PE with hemodynamic instability
• Acute myocardial infarction (AMI)
• Deep vein thrombosis (DVT)
• Arterial thrombosis

Administration Protocol

1. Initial loading dose: 250,000 IU administered intravenously over 30 minutes
2. Maintenance infusion: 100,000 IU/hour for 12-24 hours
3. Monitoring: Hemodynamic parameters should be monitored every 2-3 hours during administration 1

Special Considerations

• Hydrocortisone: Should be given with streptokinase to reduce allergic reactions 1
• Anticoagulation: Institute parenteral anticoagulation near the end of or immediately following streptokinase infusion when the partial thromboplastin time or thrombin time returns to twice normal or less
• Duration: The optimal duration depends on clinical response, but typically ranges from 12-24 hours for PE and arterial thrombosis

Efficacy and Monitoring

Streptokinase efficacy should be monitored through:

• Improvement in hemodynamic parameters
• Resolution of symptoms
• Doppler echocardiography to assess improvement in right ventricular function and pulmonary pressures in PE cases
• Fibrinogen levels and thrombin time (expect lengthening of thrombin time and decrease in fibrinogen concentration) 2

Risks and Complications

• Bleeding risk: Thrombolytic therapy carries a significant risk of bleeding, with a 13% cumulative rate of major bleeding and a 1.8% rate of intracranial/fatal hemorrhage 2
• Allergic reactions: Streptokinase is highly antigenic; its use on one occasion precludes its use in subsequent episodes due to development of neutralizing antibodies 1
• Hypotension: May occur during administration and should be monitored closely

Alternative Dosing Regimens

In specific clinical scenarios, alternative dosing regimens have been studied:

• For acute myocardial infarction, some studies have used 1,500,000 IU administered over 1 hour 3
• In severe, life-threatening pulmonary embolism with hemodynamic collapse, higher initial doses (750,000-1,000 IU) administered rapidly have been reported in case studies 4

Pediatric Considerations

In pediatric patients with persistent femoral artery thrombosis after cardiac catheterization:

• Systemic streptokinase infusion has been shown to be effective and relatively safe 2
• Monitor for lengthening of thrombin time and decrease in fibrinogen concentration
• Bleeding complications are typically localized to puncture sites 2

Comparison with Other Thrombolytics

Tissue plasminogen activator (tPA) has several advantages over streptokinase:

• More thrombus-specific
• Acts on the plasminogen-fibrin complex
• Leads to minimal decrease in systemic fibrinogen
• Non-antigenic and unaffected by anti-streptococcal antibodies 2

However, streptokinase remains a valuable option due to its established efficacy and lower cost in many healthcare systems.

Remember that the greatest benefit from thrombolytic therapy is observed when treatment is initiated within 48 hours of symptom onset, although it can still be useful in patients who have had symptoms for 6-14 days 2.