All you need to know about Anticoagulants (NOACs)

A blood clot is formed when activated platelets are trapped in stabilized cross linked fibrin. The process of fibrin formation is controlled by procoagulation and anticoagulation. If the ability of the body to maintain this equilibrium is disrupted, we could either bleed to death or become one big blood clot.

If a person has a higher risk of clot formation, there are various drugs available that work on different areas of the clotting cascade to disrupt the clotting process. There are three main types of drugs used in the management of blood clots.

Anticoagulant drugs: for people with a tendency to form clots in the slow-forming blood in the venous system. They have the ability to stabilize an existing clot so that it does not break away and become a circulation stopping embolism, but they cannot actively break down the clot. The main drugs we see which are being used are:

• Unfractionated Heparin
• Low Molecular Weight Heparin (LMWH)
• Warfarin

Antiplatelet drugs: for people with a tendency to form clots in the fast-flowing blood in the arterial system. They reduce the ability to platelets to stick together when the blood flow is disrupted; thereby reducing the risk of clot formation. This group includes drugs such as Aspirin, Clopidogrel, Abciximab, Tirofiban and Dipyridamole; which will not be covered within the scope of this article.

Thrimboltic / fibrinolytic drugs: for people requiring emergent breakdown of a clot that has already formed. These drugs are administered intravenously only in hospital following an acute blockage of a blood vessel within the heart, lung or brain. This group includes drugs such as Alteplase, Reteplase, Tenecteplase and Streptokinase

Unfractionated Heparin

Antithrombin III is one of the opposing anticoagulation factors naturally occurring within the body. It’s function is to prevent the activation of thrombin. Unfractionated Heparin, generally referred to as Heparin, blinds to antithrombin III within the blood.