Antiplatelet drugs like aspirin work by interfering with platelet function and thromboxane synthesis. Aspirin is a thromboxane synthase inhibitor that irreversibly inhibits this enzyme, reducing thromboxane production and platelet aggregation. It is commonly used at low doses of 75-150 mg daily to prevent myocardial infarction and stroke in high-risk patients by its antiplatelet effects.

1. Antiplatelet drugs
Interfere with platelet
function

2. Classification
1. TXA2 synthesis inhibitor: Aspirin
2. Others: Dipyridamole, clopidogrel, ticlopidine
abciximab

3. ASPIRIN
 Low dose aspirin (75-150 mg/day)-
selectively produce antiplatelet activity
Irreversibly inhibits thromboxane synthase
Reduces TXA2 production  antiplatelet
activity

4. Mechanism of action
Membrane phospholipids
↓
Arachidonic acid
↓
cyclic endoperoxides
↓ Thromboxane synthase
TXA2 (platelet aggregation)
Aspirin
Inhibits

5. Therapeutic uses
1. Myocardial infarction (MI)
2. Prevent MI in high risk patients
3. Reduce incidence of stroke in high
risk patients