What medications are typically administered to a patient with ST-Elevation Myocardial Infarction (STEMI)?

Common Medications Administered to STEMI Patients

The standard pharmacological management for STEMI patients includes aspirin, P2Y12 inhibitors (particularly clopidogrel), anticoagulants, nitroglycerin, beta-blockers, and ACE inhibitors, all of which work together to reduce mortality and improve outcomes. 1

Immediate Medications (First Hours)

Antiplatelet Therapy

• Aspirin: 162-325 mg loading dose (chewable or non-enteric coated) as soon as possible, followed by 75-162 mg daily maintenance dose 1, 2

  • Should be given immediately unless contraindicated by allergy or active gastrointestinal bleeding
  • Continues indefinitely for secondary prevention

• P2Y12 Inhibitors: 1, 3

  • Clopidogrel: 300-600 mg loading dose followed by 75 mg daily
  • Given in conjunction with aspirin (dual antiplatelet therapy)
  • For patients unable to take aspirin due to hypersensitivity or GI intolerance, clopidogrel is the primary alternative

Anticoagulation

• Unfractionated Heparin (UFH): IV bolus of 60 U/kg (maximum 4000 U) followed by infusion of 12 U/kg/hour (maximum 1000 U/hour) 1

  • Particularly important for patients at high risk for systemic emboli (large or anterior MI, atrial fibrillation, previous embolus, LV thrombus, or cardiogenic shock)

• Low Molecular Weight Heparin (LMWH): Alternative to UFH, especially in patients not undergoing immediate reperfusion 1

Symptom Management

• Nitroglycerin: Sublingual or aerosol, up to 3 doses at 3-5 minute intervals 1

  • Contraindicated if:
    • Hypotension (SBP <90 mmHg or ≥30 mmHg below baseline)
    • Extreme bradycardia (<50 bpm)
    • Tachycardia without heart failure (>100 bpm)
    • Right ventricular infarction

• Morphine: IV administration for chest discomfort unresponsive to nitrates 1

  • Preferred analgesic for STEMI patients with persistent pain

• Supplemental Oxygen: Should be continued beyond the first 6 hours in patients with arterial oxygen desaturation (SaO₂ <90%) or overt pulmonary congestion 1

Early In-Hospital Medications (First 24 Hours)

Beta-Blockers

• Should be initiated within the first 24 hours 1, 2
• Start with low doses after patient stabilization
• IV beta-blockers may be considered for severe hypertension or tachyarrhythmias in patients without contraindications

Renin-Angiotensin-Aldosterone System Inhibitors

• ACE Inhibitors: Start within 24 hours in patients with:

  • Anterior MI
  • Heart failure
  • LVEF <40%
  • Tachycardia 1, 2

• ARBs (e.g., valsartan): Alternative for patients intolerant to ACE inhibitors who have:

  • Clinical or radiological signs of heart failure
  • LVEF <40% 1

• Aldosterone Blockers: For patients with:

  • Heart failure
  • LVEF ≤40%
  • Serum creatinine ≤2.5 mg/dL in men or ≤2.0 mg/dL in women
  • Serum potassium ≤5.0 mEq/L 1

Statins

• High-intensity statin therapy should be initiated as early as possible 2
• Goal: LDL-C <70 mg/dL or ≥50% reduction if baseline is 70-135 mg/dL

Special Considerations

Reperfusion Strategy Medications

• Fibrinolytic Agents (when primary PCI cannot be performed within 120 minutes):
  • Tenecteplase: Single weight-based bolus, easier for pre-hospital administration
  • Alteplase: Dose adjusted for patients <67 kg
  • Reteplase: Double-bolus administration 2

Timing Considerations

• Research suggests administering aspirin before nitroglycerin (approximately 10 minutes prior) may lead to better pain control and reduced need for additional medications 4

Medication Interactions and Cautions

• NSAIDs (except aspirin) should not be administered during hospitalization for STEMI due to increased risk of mortality, reinfarction, hypertension, heart failure, and myocardial rupture 1
• Clopidogrel's effectiveness depends on CYP2C19 metabolism; poor metabolizers may need alternative P2Y12 inhibitors 3
• If CABG is planned, clopidogrel should be withheld for at least 5-7 days unless urgency outweighs bleeding risk 1

Medication Sequence Algorithm

1. Immediate (within minutes of diagnosis):

   • Aspirin 162-325 mg (chewed)
   • Oxygen if SaO₂ <90%
   • Nitroglycerin (if ongoing chest pain and no contraindications)
   • Morphine IV (if pain persists despite nitroglycerin)

2. Early (within first hour):

   • P2Y12 inhibitor (clopidogrel, prasugrel, or ticagrelor)
   • Anticoagulant (UFH or LMWH)

3. Within 24 hours:

   • Beta-blocker (oral)
   • ACE inhibitor or ARB (for indicated patients)
   • High-intensity statin

4. Before discharge:

   • Optimize doses of all medications
   • Consider aldosterone antagonist for eligible patients

This medication regimen has been shown to significantly reduce mortality, reinfarction rates, and improve long-term outcomes in STEMI patients when administered promptly and appropriately.