This is a new class of medicines that acts to directly inhibit the enzyme 'thrombin' which is involved in blood clotting.

Currently in Australia there are three of these agent available.  Two of these, lepirudin and bivalirudin, are medicines are used in specialist situations, usually only in patients in hospital.

The other agent, dabigatran, can be taken orally.  It has only recently been released in Australia and is used to prevent the formation of clots following major orthopaedic surgery, such as hip and knee replacement surgery.

The usual dose is 220mg once daily.  Some people, such as those with kidney problems or those who take a medicine called amiodarone, may need a lower dose of 150mg daily.

The length of treatment vaires but usuall dabigatran needs to be taken for 10 days following knee replacement surgery and for 28 to 35 days following hip replacement surgery.

Dabigatran is still a new medicine and further studies are underway to test its use in other conditions.

This is a new class of medicines that acts to directly inhibit one of the major clotting factors (factor Xa).

Currently rivaroxaban is the only one of these medicines available in Australia.  Rivaroxaban can be taken orally and is used ot prevent the formation of clots following major orthopaedic surgery of the lower limbs.

The usual dose is 10mg taken once daily.  The duration of treatment depends on the type of surgery.  Following hip replacement surgery, rivaroxaban is recommended for five weeks.  Following knee replacement surgery two weeks of treatment is recommended.

Rivaroxaban is still a new medicine and further studies are underway to test its use in other conditions.