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

Ticagrelor Dosing for Acute Coronary Syndrome

For patients with acute coronary syndrome, administer ticagrelor as a 180 mg oral loading dose followed by 90 mg twice daily maintenance therapy. 1

Loading Dose

• 180 mg orally as a single loading dose at the time of ACS diagnosis 1
• This loading dose applies to both NSTE-ACS and STEMI patients managed without fibrinolytic therapy 1
• The loading dose should be given regardless of whether an invasive or conservative management strategy is planned 1

Maintenance Dose

• 90 mg orally twice daily starting after the loading dose 1
• Continue for 12 months unless contraindications such as excessive bleeding risk exist 1
• The twice-daily dosing is required due to ticagrelor's relatively short 12-hour plasma half-life 1

Critical Aspirin Interaction

Maintain aspirin at ≤100 mg daily when using ticagrelor - higher aspirin doses reduce ticagrelor's effectiveness 1. The benefit of ticagrelor over clopidogrel was limited to patients taking 75-100 mg of aspirin in the PLATO trial 1. This is a unique requirement for ticagrelor and warrants a black box warning consideration 1.

Clinical Context and Timing

For NSTE-ACS:

• Ticagrelor is recommended over clopidogrel to reduce major adverse cardiovascular events (MACE) and stent thrombosis in patients undergoing PCI 1
• For patients managed conservatively without planned invasive evaluation, ticagrelor remains recommended to reduce MACE 1
• Pre-treatment may be considered as soon as the diagnosis is established, particularly if angiography timing is anticipated >24 hours 1

For STEMI:

• Administer ticagrelor in patients managed with primary PCI to reduce MACE and stent thrombosis 1
• Use clopidogrel only when ticagrelor is unavailable, cannot be tolerated, or is contraindicated 1

Pharmacodynamic Advantages

Ticagrelor achieves more rapid, consistent, and potent platelet inhibition compared to clopidogrel 1. It does not require hepatic conversion to an active metabolite, resulting in onset of action within 30 minutes and peak effect at approximately 2 hours 1. The reversible binding mechanism allows faster recovery of platelet function compared to clopidogrel 1.

Common Pitfalls and Management

Dyspnea occurs in up to 15% of patients within the first week of treatment but rarely requires discontinuation 1. Bradycardia is another unique side effect to monitor 1.

For surgical procedures: Discontinue ticagrelor at least 5 days before elective surgery to allow adequate platelet function recovery 1. This is shorter than the 7-day interruption typically recommended for clopidogrel 2.

Compliance is critical: The twice-daily dosing requirement could potentially result in adverse events in non-compliant patients, particularly after stent implantation 1. Emphasize adherence counseling at discharge.

Bleeding Considerations

While overall major bleeding rates are similar between ticagrelor and clopidogrel (11.6% vs 11.2%), ticagrelor causes modestly increased non-procedure-related major bleeding (4.5% vs 3.8%) 1. However, there is no difference in blood transfusion requirements or fatal bleeding overall 1.

Mortality Benefit

Ticagrelor reduces all-cause mortality compared to clopidogrel (4.5% vs 5.9%, P<0.001), along with cardiovascular mortality (4.0% vs 5.1%, P=0.001) at 12 months 1, 3. This mortality benefit distinguishes ticagrelor from other P2Y12 inhibitors and supports its preferential use in ACS 2.