NBME 24 Answers : Block 2 : #5 = A 55-year-old man is diagnosed with coronary artery ...

nbme24/Block 2/Question#5

A 55-year-old man is diagnosed with coronary artery ...

Decreased adherence

+5 upvote downvote
submitted by lamhtu(25),

Platelet adherence and platelet aggregation are different things and this diferrence MATTERS A LOT. Fuck you, NBME. These differences supposedly matter on some questions and not on others. Where is the consistency? Hello?

+1 upvote downvote
submitted by step1forthewin(1),

Can someone please clarify the answer. Is decreased adherence same as decreased aggregation? Wouldn;t inhibition of the IIb/IIIa receptor prevent aggregation?

xxabi I'm not completely sure...but I think its because its aspirin, and aspirin doesn't work on IIb/IIIa receptors. That's why i picked decreased adherence of platelets, figured that was the closest thing to decreased aggregation that still made sense with aspirin's mechanism of action. Hope that helps! +

ihavenolife Aspirin irreversibly inhibits COX which leads to decreased TXA2. TXA2 normally is a vasoconstrictor and induces platelet aggregation, so aspirin inhibits platelet aggregation by downplaying TXA2 not by interacting with IIb/IIIa receptor. (Source FA and UWorld) +3

fallenistand In this case, inhibition of COX-1 by aspirin will also reduce the amount of precursors for vascular prostacyclin synthesis, provided, for example, from adhering platelets https://www.ncbi.nlm.nih.gov/pubmed/9263351 +