Plavix
Meaning of Plavix: It is a prodrug: the tablet does nothing until the liver converts it, and some people carry an enzyme variant that converts it poorly.
Definition of Plavix
Plavix is a brand name for clopidogrel, an antiplatelet medicine that blocks the P2Y12 receptor on platelets. That receptor responds to a signal released by platelets already activated, and it is what recruits others to join a growing clump. Blocking it makes platelets much less likely to stick together and form a clot inside an artery.
How is it different from a blood thinner for clots in the legs?
Clots are not all the same, and the two drug families treat different ones.
| Arterial clot | Venous clot | |
|---|---|---|
| What it is made of | Mostly platelets, packed under fast flow | Mostly fibrin mesh and trapped red cells, formed in slow flow |
| Where it forms | On a ruptured deposit in an artery wall | In leg or pelvic veins, or the lungs |
| Drug family used | Antiplatelets, including clopidogrel | Anticoagulants, such as warfarin or the direct oral agents |
Why is it often paired with aspirin?
The two block different switches on the same cell. Aspirin stops platelets making thromboxane, one activating signal; clopidogrel blocks the receptor for a second, entirely separate one. Using both is called dual antiplatelet therapy and is standard for a defined period after a stent is placed or after a heart attack, because a bare metal surface inside an artery is a powerful trigger for a blood clot until the vessel lining grows over it. The length of that period is a balance, since every added week of double blockade lowers clot risk and raises bleeding risk together.
Why does the liver step matter?
Clopidogrel is swallowed in an inactive form and has no effect until liver enzymes convert it, and one enzyme in particular does most of that work. Inherited variants that reduce the activity of that enzyme leave less active drug in circulation, and some other medicines inhibit the same enzyme with a similar result. Testing for those variants is available and is used in some settings. Newer drugs in the same class do not depend on that conversion to the same degree. The blockade itself is permanent for each platelet it touches, so the effect wears off only as the body replaces its platelets over the following days.
Also known as
Used in a sentence
Plavix was continued for a defined period following placement of the coronary stent.
Good to know
Plavix reduces the clumping of platelets rather than dissolving a clot that has already formed, which distinguishes its action from medicines used to break down an established clot.