What is the recommended use and dosage of Ticagrelor (antiplatelet agent) for patients with acute coronary syndrome?

Ticagrelor in Acute Coronary Syndrome: Recommended Use and Dosage

For patients with acute coronary syndrome (ACS), ticagrelor should be administered at a loading dose of 180 mg followed by 90 mg twice daily for 12 months, regardless of initial treatment strategy. 1

Indications and Patient Selection

Ticagrelor is recommended for:

• All ACS patients (STEMI and NSTE-ACS) as a P2Y12 inhibitor in addition to aspirin 1
• STEMI patients managed with primary PCI 1
• NSTE-ACS patients regardless of whether they undergo PCI or are managed conservatively 1
• Patients previously on clopidogrel should be switched to ticagrelor (discontinue clopidogrel when ticagrelor is started) 1

Dosing Protocol

1. Loading dose: 180 mg orally 1
2. Maintenance dose: 90 mg twice daily 1
3. Duration: 12 months unless contraindicated due to excessive bleeding risk 1
4. Aspirin co-administration: 75-100 mg daily (never exceed 100 mg when combined with ticagrelor) 1, 2

Contraindications

Ticagrelor should not be used in patients with:

• Previous intracranial hemorrhage
• Ongoing active bleeding 1

Clinical Evidence Supporting Recommendation

The PLATO trial demonstrated that ticagrelor significantly reduced the composite endpoint of cardiovascular death, myocardial infarction, or stroke compared to clopidogrel (9.8% vs. 11.7%, HR 0.84) 3. Specifically:

• Reduced myocardial infarction (5.8% vs. 6.9%, p=0.005)
• Reduced cardiovascular mortality (4.0% vs. 5.1%, p=0.001)
• Reduced all-cause mortality (4.5% vs. 5.9%, p<0.001) 3

Special Considerations

• Timing of administration: In NSTE-ACS patients planned for an invasive strategy with angiography anticipated >24 hours, upstream treatment with ticagrelor may be considered 1
• Switching from clopidogrel: Patients previously exposed to clopidogrel should be switched to ticagrelor early after hospital admission with a loading dose of 180 mg, regardless of timing and loading dose of clopidogrel 1
• Bleeding risk assessment: Consider using the PRECISE-DAPT score (≥25 indicates high bleeding risk) when determining duration of therapy 1
• Perioperative management: Discontinue ticagrelor at least 3-5 days before planned surgery to minimize bleeding risk 2

Monitoring and Side Effects

• Dyspnea: Occurs in up to 15% of patients, usually mild to moderate in severity 2
• Ventricular pauses: May occur but are largely asymptomatic 4
• Bleeding risk: Similar overall major bleeding compared to clopidogrel, but higher non-CABG-related bleeding (4.5% vs. 3.8%, p=0.03) 3

Comparison with Other P2Y12 Inhibitors

• Prasugrel: In NSTE-ACS patients undergoing PCI, prasugrel should be considered in preference to ticagrelor 1
• Clopidogrel: Ticagrelor is superior to clopidogrel in reducing cardiovascular events in ACS patients 3 but clopidogrel should be used when ticagrelor is unavailable, not tolerated, or contraindicated 1

Important Cautions

• Avoid high-dose aspirin (>100 mg daily) as it may reduce ticagrelor's effectiveness 2
• Emphasize the importance of twice-daily dosing and adherence to prevent thrombotic events 2
• Monitor for bleeding complications, especially in patients with risk factors for bleeding

By following these evidence-based recommendations for ticagrelor use in ACS patients, clinicians can optimize outcomes by reducing mortality and recurrent ischemic events while managing bleeding risk.