What are the initial medications and doses for managing Non-ST-Elevation Myocardial Infarction (NSTEMI)?

Initial Medication Protocol for NSTEMI Management

Aspirin 162-325 mg loading dose (chewable) followed by 81 mg daily maintenance dose should be administered immediately upon diagnosis of NSTEMI, along with a P2Y12 inhibitor (preferably ticagrelor 180 mg loading dose followed by 90 mg twice daily), and anticoagulation with fondaparinux 2.5 mg daily or enoxaparin 1 mg/kg every 12 hours. 1, 2

First-Line Medications

Antiplatelet Therapy

1. Aspirin

   • Initial loading dose: 162-325 mg (non-enteric coated, chewable) 1, 2
   • Maintenance dose: 81 mg daily 1
   • Should be administered immediately upon presentation 1

2. P2Y12 Inhibitor (choose one):

   • Ticagrelor (preferred) 1, 2
     • Loading dose: 180 mg
     • Maintenance dose: 90 mg twice daily
   • Clopidogrel (if ticagrelor contraindicated) 1, 2
     • Loading dose: 300 mg
     • Maintenance dose: 75 mg daily
   • Prasugrel (only for PCI-treated patients) 1, 3
     • Loading dose: 60 mg
     • Maintenance dose: 10 mg daily
     • Contraindicated in patients with history of stroke/TIA
     • Consider 5 mg daily for patients <60 kg

Anticoagulation (choose one)

1. Fondaparinux (preferred for medically managed patients) 2

   • Dose: 2.5 mg subcutaneously daily

2. Enoxaparin 2

   • Dose: 1 mg/kg subcutaneously every 12 hours
   • Adjust for renal insufficiency

3. Unfractionated Heparin (for high bleeding risk or severe renal insufficiency) 2

   • Initial bolus followed by continuous infusion titrated to aPTT

Additional Medications

Anti-Ischemic Therapy

1. Beta-Blockers 1, 2

   • Initiate within 24 hours if no contraindications
   • Start with low doses and titrate
   • Avoid in hypotension or signs of heart failure

2. Nitroglycerin 2, 4

   • Sublingual: 0.4 mg every 5 minutes for chest pain (up to 3 doses)
   • IV infusion: 5-10 mcg/min, titrated for ongoing ischemia or hypertension

3. Morphine 4

   • 2-4 mg IV for refractory chest pain
   • Use cautiously as it may delay P2Y12 inhibitor absorption

Additional Supportive Therapy

1. Statins (high-intensity) 2

   • Initiate regardless of cholesterol levels
   • Atorvastatin 40-80 mg or rosuvastatin 20-40 mg

2. ACE Inhibitors/ARBs 2

   • Start once patient is hemodynamically stable
   • Particularly important in patients with LV dysfunction, hypertension, or diabetes

Special Considerations

GP IIb/IIIa Inhibitors

• Consider in high-risk patients undergoing PCI 1
• Eptifibatide or Tirofiban are preferred 1, 5
• Tirofiban dosing: 0.4 mcg/kg/min for 30 minutes, then 0.1 mcg/kg/min 5

Bleeding Risk Management

• For patients at high bleeding risk, consider:
  • Lower aspirin maintenance dose (81 mg) 1, 2
  • Proton pump inhibitors for GI protection 2
  • Shorter duration of dual antiplatelet therapy if necessary 1

Contraindications and Cautions

• Aspirin: Avoid in true aspirin allergy; consider desensitization or use single P2Y12 inhibitor 1
• Prasugrel: Avoid in patients >75 years, <60 kg, or with history of stroke/TIA 3
• NSAIDs: Discontinue immediately (except aspirin) due to increased risk of adverse events 2
• Beta-blockers: Avoid in cardiogenic shock, severe bradycardia, or high-degree AV block

Duration of Therapy

• Aspirin: Continue indefinitely 1, 2
• P2Y12 inhibitor: Continue for up to 12 months 1, 2
• Anticoagulants: Discontinue after acute phase unless specific indication for continuation 2

Common Pitfalls to Avoid

1. Delaying aspirin administration - should be given immediately upon suspicion of NSTEMI
2. Using enteric-coated aspirin for loading dose - slower absorption than non-coated formulations 1
3. Administering NSAIDs concurrently with antiplatelet therapy - increases bleeding risk 2
4. Failing to adjust anticoagulant doses in renal insufficiency
5. Overlooking potential drug interactions, especially with P2Y12 inhibitors

The evidence strongly supports immediate dual antiplatelet therapy with aspirin and a P2Y12 inhibitor, along with anticoagulation, as the cornerstone of initial NSTEMI management. Early administration of these medications has been shown to reduce mortality and recurrent ischemic events.