Ticagrelor belongs to the antiplatelet group that targets the ADP-driven $$P2Y_{12}$$ receptor on platelets.
The discriminating point among the options is the nature of binding:
• Thienopyridines - clopidogrel, prasugrel, ticlopidine - are prodrugs that bind $$P2Y_{12}$$ irreversibly for the platelet's lifespan.
• Ticagrelor is not a prodrug; it is directly active and binds the receptor reversibly at an allosteric site.
Consequences of reversible, short-acting binding:
1. It must be dosed twice daily, not once.
2. Platelet function recovers faster after stopping the drug.
Regarding bleeding, major bleeding rates were broadly comparable to clopidogrel in PLATO, so 'more cerebral bleed' is not the defining true statement. Therefore the single clearly correct option is its reversible P2Y12 inhibition.
\[\boxed{\text{Reversible P2Y12 inhibitor}}\]