There are numerous forms of anticoagulant available, with warfarin being one of the most commonly used. This drug works by inhibiting the VKORC1 gene which is involved in synthesising vitamin K. This is in turn a crucial vitamin in coagulation since factors II, VII, IX and X in the coagulation cascade are dependent on vitamin K. Therefore, since this gene is inhibited, it will result in a reduced level of vitamin K, and also a reduction in the level of the coagulation factors mentioned above. The end result of this is that the blood will be less likely to clot.

Another anti-coagulant is heparin. This can be in two forms, unfractionated and low molecular weight heparin. Both however have the same effect in that they bind to anti-thrombin III in the coagulation cascade. This factor is a normal break in the coagulation cascade, and when heparin binds to it, it further enhances its coagulation effect, again reducing the chance of clotting.

Furthermore, Dabigatran and Ximelagatran are anticoagulants that work as direct thrombin inhibitors. These work by blocking the action of the enzyme thrombin otherwise known as factor II in the coagulation cascade. By blocking this, it will the level of prothrombin which is required to activate the other cofactors in the pathway which would otherwise result in a clot.

Due to the fact that all of these drugs result in the thinning of blood, they have numerous uses. They are commonly used in those that have previously had a MI so that in the event that another takes place, reperfusion of the heart can occur quickly. It can also be used in those with unstable angina where they have narrowed arteries and therefore reduced blood flow to the heart. It can also be used in those with an embolism, such as deep vein thrombosis.

 

However, these anticoagulants have various side effects and drug interactions which can be read here.