What is the appropriate dual antiplatelet therapy dosing (aspirin and a P2Y12 inhibitor) for a woman under 75 years old, weighing over 60 kg, with acute coronary syndrome and planned percutaneous coronary intervention, assuming no contraindications?

DAPT Dosing for ACS with Planned PCI

For a woman under 75 years old, weighing over 60 kg, with acute coronary syndrome and planned PCI, administer aspirin 162-325 mg loading dose (chewed if possible) followed by 75-100 mg daily, plus either ticagrelor 180 mg loading dose followed by 90 mg twice daily OR prasugrel 60 mg loading dose followed by 10 mg daily for 12 months. 1

Aspirin Dosing

• Loading dose: 162-325 mg orally, chewed when possible for faster onset 1

  • Administer even if patient is already on aspirin
  • Can use rectal or IV routes if oral not feasible

• Maintenance dose: 75-100 mg daily (non-enteric coated) 2, 1

  • This low-dose regimen is critical—doses ≤100 mg daily must be used with ticagrelor based on PLATO trial findings 1
  • Higher maintenance doses (300-325 mg) showed no superiority but increased bleeding risk 1

P2Y12 Inhibitor Selection and Dosing

First-line options (in order of preference):

Ticagrelor (Preferred)

• Loading: 180 mg orally 2, 1
• Maintenance: 90 mg twice daily 2, 1
• Recommended regardless of initial treatment strategy (Class I, Level B) 2
• Can be given even if patient pre-treated with clopidogrel (discontinue clopidogrel when starting ticagrelor) 2

Prasugrel (Alternative first-line)

• Loading: 60 mg orally 2, 1
• Maintenance: 10 mg daily (for patients ≥60 kg and <75 years) 1
• Recommended for P2Y12 inhibitor-naïve patients undergoing PCI (Class I, Level B) 2
• Your patient meets criteria: <75 years, >60 kg, no contraindications

Clopidogrel (Reserve for contraindications)

• Loading: 600 mg orally 2
• Maintenance: 75 mg daily 2
• Use only if ticagrelor or prasugrel contraindicated (prior intracranial hemorrhage, oral anticoagulation indication) 2

Duration

Continue DAPT for 12 months unless excessive bleeding risk (e.g., PRECISE-DAPT score ≥25) 2

Critical Caveats

• Prasugrel contraindications to verify: No prior stroke/TIA, no prior intracranial hemorrhage, no active bleeding 2
• Ticagrelor contraindications: No prior intracranial hemorrhage, no active bleeding 2
• Add PPI to reduce GI bleeding risk while on DAPT 2
• Radial access preferred for PCI if operator experienced 2
• Do not perform routine platelet function testing to adjust therapy 2

Practical Implementation

Given your patient's profile (woman, <75 years, >60 kg, no stated contraindications), either ticagrelor or prasugrel is appropriate. Recent evidence suggests ticagrelor may have slight advantages in reducing MACE and mortality compared to clopidogrel 3, while prasugrel showed superiority over ticagrelor in the ISAR-REACT-5 trial 4. Both are Class I recommendations with Level B evidence 2.

The choice between ticagrelor and prasugrel can be based on:

• Twice-daily dosing tolerance (ticagrelor requires BID dosing)
• Dyspnea history (ticagrelor associated with dyspnea)
• Cost and availability