Which of the following is a reversible P2Y12 antagonist?

Cangrelor is identified as a reversible P2Y12 antagonist, which means it can temporarily inhibit the P2Y12 receptor on the surface of platelets, leading to a reduction in platelet aggregation. This reversibility is particularly significant for clinical settings, as it allows for rapid adjustments in antiplatelet therapy. If a patient experiences bleeding or requires surgery, the effects of cangrelor can be reversed quickly, making it a suitable option in acute care situations.

In contrast, the other options listed are not reversible. Ticlopidine and clopidogrel are both prodrugs that irreversibly modify the P2Y12 receptor, which prevents platelet activation for the life of the platelet (approximately 7 to 10 days). Prasugrel also acts as an irreversible P2Y12 antagonist with similar prolonged effects. This irreversible binding can be an advantage in some contexts, yet it poses challenges when requiring rapid cessation of platelet inhibition. Thus, the unique property of cangrelor as a reversible antagonist makes it distinctly useful in certain clinical scenarios.