A 62-year-old man received streptokinase for an anterior STEMI eight months ago. He now presents with an inferior STEMI within 90 minutes of symptom onset, and primary PCI is unavailable. Which thrombolytic is most appropriate?

• A Streptokinase again, at double dose
• B Alteplase or tenecteplase ✓
• C Urokinase followed by streptokinase infusion
• D Aspirin and clopidogrel alone, deferring reperfusion

Explanation

Streptokinase is a bacterial protein that induces neutralizing anti-streptokinase antibodies, which appear within days and persist for months to years, blunting any repeat administration. Re-exposure can also cause severe allergic reactions and hypotension. Fibrin-selective agents such as alteplase and tenecteplase are non-antigenic human tissue plasminogen activator derivatives and remain fully effective after prior streptokinase exposure.

Reference: Katzung Basic and Clinical Pharmacology, 15th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.