Australian Dental Council (ADC) Test 2025 – 400 Free Practice Questions to Pass the Exam

Aspirin is known to inhibit the enzyme cyclooxygenase (COX), which plays a vital role in the synthesis of various eicosanoids, including thromboxane A2. Thromboxane A2 is a potent vasoconstrictor and promotes platelet aggregation, which is essential for normal blood clotting. By inhibiting the production of thromboxane A2, aspirin reduces the ability of platelets to aggregate effectively, leading to an increased risk of bleeding, especially in postoperative patients who may require coagulation.

In contrast, although prostacyclin, thrombin, and prostaglandins play roles in vascular function and hemostasis, the direct impact of aspirin on thromboxane A2 is the critical factor that leads to increased postoperative bleeding. Prostacyclin is generally associated with vasodilation and inhibition of platelet aggregation, and while thrombin is a key enzyme in the coagulation cascade, it is not directly affected by aspirin in the same way as thromboxane A2. Prostaglandins, derived from the same pathway, also have diverse functions related to inflammation and pain but are not the primary substance linked to aspirin's effect on bleeding risk. Hence, thromboxane A2's inhibition specifically under