When can the next dose of streptokinase be given after initial administration?

Streptokinase Re-administration Timing

Streptokinase is absolutely contraindicated within 6 months of previous exposure due to the development of persistent neutralizing antibodies that can cause serious allergic reactions and render the drug ineffective. 1

Critical Timing Restriction

• Streptokinase should never be re-administered within 6 months of initial use 1
• This is classified as an absolute contraindication in major cardiology guidelines 1
• The restriction applies regardless of clinical urgency or indication 1

Mechanism Behind the Restriction

Streptokinase is highly antigenic, meaning it triggers a robust immune response: 1

• Antistreptokinase antibodies develop rapidly starting from 4 days after initial administration 2
• Neutralization titers can persist for at least 4-10 years in up to 50% of patients 2, 1
• These antibodies can reach levels that completely neutralize subsequent doses, making the drug ineffective 2
• High antibody titers are associated with lower coronary reperfusion rates and increased risk of serious allergic reactions including anaphylaxis 2

Alternative Thrombolytic Options for Re-treatment

If thrombolysis is needed after prior streptokinase exposure, use fibrin-specific agents instead: 1

• Alteplase (tPA) - does not cause antibody formation and can be safely re-administered 1
• Reteplase (rPA) - non-antigenic, safe for repeat dosing 1
• Tenecteplase (TNK-tPA) - non-antigenic, given as single bolus 1

These fibrin-specific agents do not result in antibody formation and have no restrictions on re-administration timing 1

Clinical Scenarios Requiring Re-treatment

If re-occlusion or reinfarction occurs with recurrent ST-segment elevation after initial streptokinase: 1

• Within 6 months: Use alteplase, reteplase, or tenecteplase - never repeat streptokinase 1
• After 6 months: Streptokinase may theoretically be considered, though fibrin-specific agents remain preferred 1
• Mechanical revascularization (PCI) is preferred over repeat thrombolysis when available 1

Important Caveats

• The 6-month restriction also applies to anistreplase (APSAC), which contains streptokinase and shares the same antigenic properties 1
• Streptokinase is no longer marketed in the United States but remains available in other countries where cost considerations may favor its use 1
• Re-administration of any fibrinolytic agent carries increased risk of excessive bleeding complications regardless of antibody status 1