What are the drugs for myocardial infarction (MI) management?

Drugs for Myocardial Infarction Management

The essential drugs for myocardial infarction management include aspirin (162-325 mg loading dose), P2Y12 inhibitors (such as clopidogrel), anticoagulants, beta-blockers, ACE inhibitors, and statins, with the specific regimen depending on whether the patient is receiving primary PCI or fibrinolytic therapy. 1

Initial Emergency Medications

• Aspirin: 162-325 mg loading dose immediately upon diagnosis 1

  • Chewable form preferred for rapid absorption (reaches maximum platelet inhibition within 30 minutes) 2
  • Continue with 75-100 mg daily indefinitely 1

• Nitroglycerin: 0.4 mg sublingually every 5 minutes (up to 3 doses) for ongoing chest pain if systolic BP >90 mmHg 1

• Morphine: 2-4 mg IV with additional 2-8 mg every 5-15 minutes as needed for pain unrelieved by nitroglycerin 1

• Oxygen: Administer only if oxygen saturation <94% 1

Reperfusion Strategy-Specific Medications

For Primary PCI Approach (preferred when available within 90-120 minutes)

• Dual Antiplatelet Therapy (DAPT):

  • Aspirin 162-325 mg loading dose, then 75-100 mg daily indefinitely 1
  • P2Y12 inhibitor: Clopidogrel 300 mg loading dose (if ≤75 years old), then 75 mg daily for 12 months 1, 3
    • Note: Consider alternative P2Y12 inhibitor in CYP2C19 poor metabolizers 3

• Anticoagulation: Until revascularization or hospital discharge (up to 8 days)

  • Enoxaparin preferred over unfractionated heparin 1
  • Avoid fondaparinux due to risk of catheter thrombosis 1

For Fibrinolytic Therapy (when PCI not available within 120 minutes)

• Fibrinolytic agents: Prefer fibrin-specific agents (tenecteplase, alteplase, or reteplase) 1

  • Absolute contraindications include history of intracranial hemorrhage, significant head/facial trauma, uncontrolled hypertension, ischemic stroke, active bleeding, or suspected aortic dissection 1
  • Higher risk of intracranial hemorrhage in patients ≥75 years old 1

• Adjunctive antithrombotic therapy:

  • Aspirin 162-325 mg loading dose, then 75-100 mg daily 1
  • Clopidogrel 300 mg loading dose (if ≤75 years old), then 75 mg daily 1, 3
  • Anticoagulation (enoxaparin preferred) 1

Post-MI Medications (Regardless of Reperfusion Strategy)

• Beta-blockers: Start within 24 hours for hemodynamically stable patients 1

  • Particularly indicated for patients with heart failure and/or LVEF <40% 1

• ACE inhibitors: Start within 24 hours for patients with:

  • Evidence of heart failure
  • LV systolic dysfunction
  • Diabetes
  • Anterior infarct 1, 4
  • Example: Lisinopril 5 mg within 24 hours of symptom onset, 5 mg after 24 hours, then 10 mg daily (reduce to 2.5 mg if systolic BP <120 mmHg) 4

• High-intensity statin therapy: Start as early as possible

  • Target LDL-C <1.8 mmol/L (70 mg/dL) or ≥50% reduction 1

Post-Fibrinolysis Management

• Transfer to a PCI-capable center immediately after fibrinolysis 1
• Rescue PCI indicated if fibrinolysis fails (<50% ST-segment resolution at 60-90 min) 1
• Routine angiography recommended 2-24 hours after successful fibrinolysis 1

Important Medication Cautions

• Avoid NSAIDs (except aspirin) due to increased risk of mortality, reinfarction, and heart failure 1
• Avoid calcium channel blockers as they have not shown mortality benefit and may be harmful in certain patients 1
• Avoid oral nitrates in acute MI; use IV nitroglycerin instead 1
• Monitor for bleeding risk with antiplatelet and anticoagulant therapy, especially in elderly patients 1, 5

Long-term Medication Management

• Dual antiplatelet therapy (aspirin + P2Y12 inhibitor) for 12 months 1, 3
• Beta-blockers, especially for reduced ejection fraction 1
• ACE inhibitors for patients with heart failure, LV dysfunction, diabetes, or anterior MI 1, 4
• High-intensity statin therapy indefinitely 1
• Cardiac rehabilitation recommended for all patients 1