An anticoagulant is a type of medication that may be used to prevent blood from coagulating or clotting. There may kinds of anticoagulants and they have different ways of acting. The majority of them are medications that are administered to people to prevent blood clotting in certain illness, but sometimes in lab or medical settings an anti-coagulant is used to prevent things like clogging of intravenous lines or of blood clotting in test tubes and syringes. For medical use in people, it’s also important to mention anti-platelet medications, which have a similar purpose to anticoagulants, though the way they work is different.
There are a number of different ways that an anticoagulant may work to keep blood from clotting. Some of the best-known ones like warfarin (Coumadin®) inhibit Vitamin K’s action and are called coumarines. Other medications may inhibit thrombin, which is an enzyme in the blood that aids in blood clotting. Such medications are less commonly used for daily anticoagulant therapy because they must be injected, but they include drugs like hirudin, melagatrane, and lepirudin. Other medications like heparin may act on thrombin indirectly by producing anti-thrombin, and are useful both as a medicine for people and to prevent clotting in medical equipment and supplies.
The category of anti-platelet medications is worth mentioning too. These prevent blood clots in a different manner, by preventing what is called platelet aggregation. The term simply means that platelets, a necessary part of blood, have a tendency to collect at the site of injuries to help stop bleeding. When a person is prescribed an anti-platelet mediation, it is an attempt to stop aggregation that might occur inside of the body and form dangerous blood clots. Common anti-platelet medications include aspirin and Plavix®.
Anticoagulant therapy, and sometimes anti-platelet therapy, may be used when people have certain heart problems. There is significant need to prevent the possibility of blood clots forming, which may be more likely if people have a an artificial valve or shunt, or if they have other conditions like deep vein thrombosis, atherosclerosis, or atrial fibrillation. Therapy usually involves taking anticoagulants like warfarin daily, and people must have blood tests frequently to make sure blood clotting is reduced enough, but not too much. Many people go to anticoagulation or warfarin clinics to have their blood levels monitored. There are some risks to this treatment, particularly if things like head injury occur, but with some watchfulness, taking things like warfarin can greatly decrease risk of stroke or pulmonary embolism.
Sometimes an anticoagulant medication is used for a very short time period after a person has had heart surgery, or directly after a stroke. Anti-platelet drugs also have some use in this respect. In general, anticoagulants tend to prevent blood clotting more than do anti-platelet meds, yet anti-platelet medications are extremely helpful. Most physicians usually advise taking an aspirin when people suspect they are having a heart attack or stroke, as this may significantly reduce damage.