An Anticoagulant is a substance used to prevent blood clots. It is useful for patients who (i) are at an increased risk of large abnormal blood clots (ex. have high cholesterol, or high blood pressure) (ii) have had heart valve surgery, (iii) have a prosthetic valve made of synthetic material, and (iv) have atrial fibrillation.
MORE INFO: Clotting is an important property of blood. It is sometimes desirable that such clotting of blood be prevented. Anticoagulants are used both inside and outside the human body to prevent the clotting of blood.
USE OF ANTICOAGULANT IN HUMANS: Example 1:
Thrombosis : The formation of a blood clot (thrombus) inside a blood vessel is described as Thrombosis. Such blood clots obstruct the flow of blood through the circulatory system. For example, your blood clots when you cut yourself so that you will not bleed to death. In cases where thrombosis is causing disease, anticoagulants can be used (at carefully controlled dosages) to reduce the tendency to clotting.
Common anticoagulants for this use are Warfarin, Heparin (various heparins exist), and nicoumalone.
USE OF ANTICOAGULANT OUTSIDE HUMAN BODY: Anticoagulants are also used to prevent the clotting of blood outside the body.
1) Blood transfusion bags : Blood is collected from donors and stored into sterile plastic bags. To maintain the fluid state of blood, it is necessary to prevent the clotting of blood. Chemicals like Acid Citrate Dextrose (ACD) and Citrated Phosphate Dextrose (CPD) can be added to stop blood clotting
2) Medical and surgical equipments: If blood is allowed to clot, these equipments will get clogged up and thus will no longer work. To prevent this from happening suitable anticoagulants are used