[san.usmle]

Prostaglandin (PGH2) is the precursor for thromboxanes & prostacyclins both.
Aspirin inhibits COX and that's how it prevents the formation of PGH2.
So how come, aspirin inhibits the synthesis of thromboxanes but not of prostacyclins? I must be missing something here.
If anyone can help with this concept please. Thanks

 

[MedicalStudent93]

Aspirin inhibits COX1 and 2 irreversibly leading to decreased synthesis of TXA2, PGI2, PGE2. Synthesis of TXA2(cause platelet aggregation) is reduced to a greater extent as compared to PGI2 (antiplatelet effect) thus the net effect is actually antiplatelet.

Hope it helps.