What medications are used for thrombolytic treatment of ST-Elevation Myocardial Infarction (STEMI)?

Medications for Thrombolytic Treatment of STEMI

Use a fibrin-specific thrombolytic agent—specifically tenecteplase, alteplase, or reteplase—as the primary thrombolytic medication for STEMI when fibrinolysis is the chosen reperfusion strategy. 1

Primary Thrombolytic Agents

The 2017 ESC Guidelines provide Class I, Level B recommendations for the following fibrin-specific agents 1:

• Tenecteplase - Single bolus administration over 5 seconds, weight-adjusted dosing 2
• Alteplase - Infusion over approximately 90 minutes 1
• Reteplase - Double bolus administration given 30 minutes apart 1, 3

For patients ≥75 years of age, consider using half-dose tenecteplase to reduce bleeding risk while maintaining efficacy 1.

Essential Adjunctive Antiplatelet Therapy

Thrombolytic therapy must always be combined with antiplatelet agents 1:

• Aspirin (oral or IV): Class I, Level B recommendation - administer as soon as possible 1
• Clopidogrel: Class I, Level A recommendation - indicated in addition to aspirin 1
  • Loading dose of 300 mg is reasonable for patients <75 years 1
  • Continue for at least 14 days, with consideration for up to 12 months 1

Mandatory Anticoagulation Co-Therapy

Anticoagulation is required in all patients receiving thrombolytics until revascularization or for hospital duration up to 8 days 1:

Preferred anticoagulant options (in order):

1. Enoxaparin (IV bolus followed by subcutaneous): Class I, Level A - preferred over UFH 1
2. Unfractionated heparin (UFH): Class I, Level B - weight-adjusted IV bolus followed by infusion 1
3. Fondaparinux: Class IIa, Level B - specifically for patients treated with streptokinase (non-fibrin-specific agent) 1

Critical caveat: Do not switch between enoxaparin and UFH once initiated, as this significantly increases bleeding risk 1.

Timing and Administration

Initiate fibrinolytic therapy as soon as possible after STEMI diagnosis, preferably in the pre-hospital setting (Class I, Level A) 1. The greatest mortality benefit occurs when treatment is given within 6 hours of symptom onset, with 30 fewer deaths per 1000 patients treated 1. Efficacy decreases substantially after 3 hours, making primary PCI increasingly preferable as time from symptom onset increases 1.

Important Clinical Pitfalls

Avoid fondaparinux as sole anticoagulation during PCI - it increases catheter thrombosis risk and requires additional UFH or bivalirudin 1. When fondaparinux is used with fibrin-specific agents (alteplase, reteplase, tenecteplase), there is no advantage over UFH and potentially worse outcomes 1.

Streptokinase is not recommended as a first-line agent when fibrin-specific thrombolytics are available, despite lower cost, due to inferior outcomes particularly in patients presenting within 6 hours 4. The newer agents (tenecteplase, alteplase, reteplase) demonstrate superior mortality reduction at 1 month and 1 year compared to streptokinase 5.