Which of the following P2Y12 antagonists is known for its rapid onset of action?

Ticagrelor is recognized for its rapid onset of action compared to other P2Y12 antagonists. This attribute is primarily due to its pharmacokinetic profile, which allows it to quickly inhibit platelet aggregation. Following oral administration, ticagrelor achieves peak plasma concentrations in about 1 to 2 hours, resulting in faster antiplatelet effects, which are particularly beneficial in acute coronary syndrome scenarios where immediate platelet inhibition is critical.

In contrast, clopidogrel and ticlopidine have a delayed onset of action as they require metabolic activation, which takes longer to achieve effective platelet inhibition. Prasugrel, while faster than clopidogrel, still does not match the rapid effects of ticagrelor, particularly in the early hours after dosing. As such, ticagrelor's attributes make it the preferred choice in situations requiring immediate anticoagulation.