Drug class · Arteries
Antiplatelet drugs
Also known as: platelet inhibitors
Medicines that stop platelets clumping into the clots that block arteries. The backbone of treatment after heart attacks, strokes and stents.
- Biological target
- Cyclo-oxygenase 1 (COX-1)
- Also called
- platelet inhibitors
Mechanism of action
Platelets plug damaged vessels by sticking to each other; in a diseased artery the plug becomes the clot that causes a heart attack or stroke. Low-dose aspirin permanently disables COX-1 in platelets so they cannot make thromboxane; clopidogrel, ticagrelor and prasugrel block the P2Y12 receptor that responds to ADP. After a stent both are used together for months, because a clot on the stent is a catastrophe.
Members of the class
Members with a page on this site are linked.
Conditions treated
Class effects
- Bruising and prolonged bleeding
- Stomach irritation and ulcers (aspirin)
- Breathlessness with ticagrelor
Cautions
- Not for primary prevention in healthy people
- Combined with an anticoagulant only on specialist advice
- A proton pump inhibitor protects the stomach in those at risk
Class warnings
- Bleeding, especially gastrointestinal, is the main class hazard; a proton pump inhibitor is often co-prescribed for those at risk, and antiplatelets are not stopped before procedures without the prescriber's advice, particularly after stents. UK
Class interactions
| With | Effect | Source |
|---|---|---|
| Anticoagulants | Additive bleeding risk; combinations are used only for specific indications under supervision. | UK |
| NSAIDs | Additive gastrointestinal bleeding, and ibuprofen can blunt aspirin's antiplatelet effect if taken beforehand. | UK |
| SSRIs and corticosteroids | Increased gastrointestinal bleeding risk. | UK |
| Omeprazole and esomeprazole (with clopidogrel) | Reduce activation of clopidogrel; an alternative PPI is preferred. | UK |
Therapeutic duplication. Aspirin with another antiplatelet (dual antiplatelet therapy) is a deliberate, time-limited prescription after stents and acute coronary syndromes; taking two antiplatelets without such an indication adds bleeding risk. UK
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Educational content. A drug class page describes what a family of medicines has in common. Individual medicines differ in dose, licensing and interactions; treatment choices belong to a prescriber.