What are the recommended medication regimens and dosing for acute coronary syndrome management, including antiplatelet therapy, anticoagulation, statin, beta‑blocker, ACE inhibitor, nitrates, morphine, and gastro‑protection?

Acute Coronary Syndrome Medication Regimens with Dosing

For all patients with ACS, immediately administer aspirin 162-325 mg orally (chewed, nonenteric coated) as a loading dose, followed by 75-100 mg daily maintenance, combined with a P2Y12 inhibitor based on the specific clinical scenario. 1

Antiplatelet Therapy

Aspirin

• Loading dose: 162-325 mg orally (chewed if possible for faster onset)
  • Give even if patient already on aspirin
  • If unable to take oral: use rectal or IV formulations
• Maintenance dose: 75-100 mg daily (nonenteric coated)
  • Critical: Use ≤100 mg daily if patient receives ticagrelor 1

P2Y12 Inhibitors (Dual Antiplatelet Therapy)

For NSTE-ACS or STEMI without fibrinolytic:

Ticagrelor (preferred for STEMI with primary PCI):

• Loading: 180 mg orally
• Maintenance: 90 mg twice daily 1

Prasugrel (for PCI patients):

• Loading: 60 mg orally
• Maintenance: 10 mg daily if weight ≥60 kg and age <75 years
• Maintenance: 5 mg daily if weight <60 kg or age ≥75 years (use with caution) 1

Clopidogrel (alternative when prasugrel/ticagrelor not suitable):

• Loading: 300-600 mg orally
• Maintenance: 75 mg daily 1

For STEMI with fibrinolytic:

• Clopidogrel loading: 300 mg if age ≤75 years; 75 mg if age >75 years
• Maintenance: 75 mg daily 1

Anticoagulation (Parenteral)

Options include (choose one based on institutional protocols and bleeding risk):

• Unfractionated heparin
• Low-molecular-weight heparin (enoxaparin)
• Bivalirudin
• Fondaparinux 2

Statin Therapy

Initiate high-intensity statin immediately on day 1, regardless of baseline cholesterol:

• Atorvastatin 80 mg daily (preferred) 3

Beta-Blocker

Initiate beta-blocker therapy during hospitalization for patients without contraindications (cardiogenic shock, heart block, severe bradycardia, decompensated heart failure) 2, 4

ACE Inhibitor

Start ACE inhibitor early during hospitalization for:

• All patients post-MI, especially with:
  • Left ventricular dysfunction
  • Heart failure
  • Anterior MI
  • Diabetes 2, 3

Nitrates

Sublingual nitroglycerin:

• 0.4 mg sublingual every 5 minutes × 3 doses for chest pain relief
• Contraindications: Recent phosphodiesterase-5 inhibitor use:
  • Within 12 hours of avanafil
  • Within 24 hours of sildenafil/vardenafil
  • Within 48 hours of tadalafil
• Avoid if: Right ventricular infarction, systolic BP <90 mmHg, or BP drop >30 mmHg below baseline 1

IV nitroglycerin:

• For persistent ischemia or hypertension
• Monitor for tachyphylaxis after ~24 hours 1

Morphine/Opioid Analgesia

Use only for pain resistant to maximally tolerated anti-ischemic medications:

Morphine:

• 2-4 mg IV, may repeat every 5-15 minutes
• Doses up to 10 mg may be considered 1

Fentanyl:

• 25-50 μg IV, may repeat
• Doses up to 100 μg may be considered 1

Important caveat: Opioids may delay absorption and pharmacodynamic effects of oral P2Y12 inhibitors, though clinical relevance is disputed. Monitor closely for adverse effects. 1

Gastro-Protection

Proton pump inhibitor (PPI):

• Recommended for patients at higher-than-average risk of GI bleeding receiving dual antiplatelet therapy and/or anticoagulation 2
• Risk factors include: history of GI bleeding, peptic ulcer disease, advanced age, concurrent NSAID use, anticoagulation

Critical Pitfalls to Avoid

• Never use NSAIDs for ischemic pain management—associated with increased MACE without benefit 1
• Do not use enteric-coated aspirin for loading dose—delays onset of action 1
• Avoid high-dose aspirin maintenance (300-325 mg daily)—increases bleeding without reducing MACE compared to low-dose 1
• Check for PDE5 inhibitor use before administering nitrates—can cause life-threatening hypotension 1