Antiplatelet therapy refers to medications that reduce the tendency of platelets (small blood cells involved in clotting) to clump together and form blood clots within blood vessels. By inhibiting platelet aggregation, antiplatelet drugs reduce the risk of heart attacks, stroke, and stent thrombosis in people with [coronary artery disease](/glossary/coronary-artery-disease/) and related conditions.
The most commonly used antiplatelet drugs in cardiac care are:
– **Aspirin:** a low-dose daily aspirin (usually 75mg) is widely prescribed for secondary prevention after [heart attack](/glossary/heart-attack/), [PCI](/glossary/percutaneous-coronary-intervention/), or [CABG](/glossary/coronary-artery-bypass-graft/). It irreversibly inhibits thromboxane A2, a chemical that promotes platelet aggregation.
– **P2Y12 inhibitors:** include clopidogrel, ticagrelor, and prasugrel. These block a different platelet pathway and are more potent than aspirin alone. After stent insertion, a combination of aspirin and a P2Y12 inhibitor (dual antiplatelet therapy, or DAPT) is prescribed for a period of months to years to prevent stent thrombosis.
Antiplatelet therapy is distinct from [anticoagulation](/glossary/anticoagulation/): antiplatelet drugs act on platelets, while anticoagulants act on clotting factors in the coagulation cascade. Some patients require both simultaneously (for example, someone with [atrial fibrillation](/glossary/atrial-fibrillation/) who has also had a stent inserted), though this combination increases bleeding risk and requires careful management.
For [cardiac arrest](/glossary/cardiac-arrest/) survivors whose arrest was caused by a [heart attack](/glossary/heart-attack/), antiplatelet therapy forms a core component of [secondary prevention](/glossary/secondary-prevention/). Side effects include increased bleeding risk; patients should inform dentists and other clinicians before any procedures.
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