Anticoagulants are a type of medicine that prevent the blood from clotting as quickly or as effectively as normally.

what are anticoagulantsSometimes they are referred to as 'blood thinners' however they don't actually make the blood thinner, they affect the clotting process in the body so that the  blood doesn't clot so easily.

Anticoagulants are used to treat and prevent blood clots that may occur in the blood vessels. Blood clots can block an artery or a vein. A blocked artery can stop blood and oxygen from getting to the heart, brain or lungs and the tissue supplied by a block artery can become damaged and may die and this can cause serious problems such as a heart attack, stroke or pulmonary embolism. A blood clot in a large vein such a in the leg vein is known as deep vein thrombosis. This can lead to complications if a piece of the clot breaks off and travels to the lung causing a pulmonary embolism.

There are several types of anticoagulants available:

Oral anticoagulants include Apixaban, Dabigatran, Edoxaban, Rivaroxaban and Warfarin.

Warfarin is a dose adjusted medicine and people taking this drug must have their blood levels checked regularly to ensure that they are within the prescribed International Normalised Ratio (INR) to reduce the risk of clots or bleeds. Warfarin can be precribed for atrial fibrillation, mechanical heart valve replacements, thrombophilia  (clotting disorders or syndromes whereby the individual is at a heightened risk of a clotting episode), deep vein thrombosis (DVT) and pulmonary embolism (PE).

Apixaban, Dabigatran, Edoxaban and Rivaroxaban  (also known as NOACS or DOACS)  work in a different way to warfarin and do not need to be monitored by regular blood tests.  Apixaban, Dabigatran, Edoxaban and Rivaroxaban can be given to reduce the  risk of stroke for people with non-valvular atrial fibrillation. Apixaban, Dabigatran, Edoxaban and Rivaroxaban can be used  for treating and preventing deep vein thrombosis and pulmonary embolism. Apixaban, Dabigatran and Rivaroxaban can be given to people who have undergone total knee and hip replacement to prevent blood clots occurring after surgery.


Heparin is an injectable anticoagulant. Standard heparin is given intravenously (IV) directly through a vein and usually in the arm. This is usually administered in hospital

Low molecular weight heparin (LMWH) is injected into the skin usually in the tummy area. People can be taught to self-inject or be supported by a healthcare professional or carer.  LMWH does not need to be monitored and different doses can be given for prevention and treatment for existing clots.


Aspirin is not an anticoagulant. It is an antiplatelet and is used in low doses to reduce the stickiness of platelets in the blood. Aspirin has historically been prescribed for some people with cardivascular disease and to reduce clot risk for those with atrial fibrillation.  The National Institute for Health and Care Excellence (NICE) no longer recommends its use as a monotherapy (by itself) for stroke prevention in atrial fibrillation as the anticoagulants can offer better protection against blood clots.