Streptokinase Dosing for Pulmonary Thromboembolism Thrombolysis
The recommended dose of streptokinase for pulmonary thromboembolism (PTE) thrombolysis is 250,000 IU as a loading dose over 30 minutes, followed by 100,000 IU/hour intravenously for 12-24 hours. 1
Standard Dosing Regimen
The European Society of Cardiology (ESC) guidelines provide clear recommendations for streptokinase dosing in PTE:
Standard regimen:
- Loading dose: 250,000 IU over 30 minutes
- Maintenance: 100,000 IU/hour for 12-24 hours 1
Accelerated regimen:
- 1.5 million IU over 2 hours 1
Indications for Thrombolysis
Thrombolytic therapy is primarily indicated for:
- High-risk PTE with cardiogenic shock and/or persistent arterial hypotension 1, 2
- Hemodynamically unstable patients 1
Thrombolysis is generally not recommended for non-high-risk patients unless they have intermediate-risk PTE with clinical deterioration 1.
Monitoring During Treatment
During streptokinase administration:
- Monitor hemodynamic parameters every 2-3 hours 1
- Perform Doppler echocardiography to assess improvement in right ventricular function and pulmonary pressures 1
- Consider stopping infusion when pressure gradient and valve area return to normal or near normal 1
- If no hemodynamic improvement is seen at 24 hours or after 72 hours without complete recovery, consider stopping the infusion 1
Efficacy Considerations
Research evidence supports the effectiveness of streptokinase for PTE:
- A study comparing 2-hour regimens of streptokinase (1.5 million IU) with alteplase showed similar hemodynamic efficacy at 2 hours, despite alteplase showing faster initial improvement 3
- High-dose, short-term streptokinase (1.5 million IU over 1 hour) has shown efficacy in reversing acute pulmonary arterial hypertension and improving right ventricular function 4
Contraindications
Absolute contraindications:
- Hemorrhagic stroke or stroke of unknown origin at any time
- Ischemic stroke in preceding 6 months
- Central nervous system damage or neoplasms
- Recent major trauma/surgery/head injury (within preceding 3 weeks)
- Gastrointestinal bleeding within the last month
- Known bleeding 1
Relative contraindications:
- Transient ischemic attack in preceding 6 months
- Oral anticoagulant therapy
- Pregnancy or within 1 week post-partum
- Non-compressible punctures
- Traumatic resuscitation
- Refractory hypertension (systolic BP >180 mmHg)
- Advanced liver disease
- Infective endocarditis
- Active peptic ulcer 1
Important Clinical Considerations
- Hydrocortisone should be given with streptokinase to reduce allergic reactions 1
- Streptokinase is highly antigenic, and its use on one occasion precludes its use in subsequent episodes due to development of neutralizing antibodies 1
- If streptokinase fails to produce a lytic state (no increase in D-dimer and aPTT, no decrease in fibrinogen at 24h), consider switching to urokinase 1
- The greatest benefit is observed when treatment is initiated within 48 hours of symptom onset, but thrombolysis can still be useful in patients with symptoms for 6-14 days 1
Risk of Bleeding
Thrombolytic therapy carries a significant risk of bleeding:
- 13% cumulative rate of major bleeding
- 1.8% rate of intracranial/fatal hemorrhage 1
In weighing risks against benefits, contraindications that are absolute in other conditions might become relative in immediately life-threatening, high-risk PTE 1.
If unsuccessful thrombolysis occurs, surgical intervention may be considered 24 hours after discontinuation of the infusion 1.