Warfarin is a common anticoagulant prescribed to prevent the formation of blood clots (thrombosis) and their migration elsewhere in the body (thromboembolism).
It is often used to treat people at higher risk of thrombosis, due to genetics, artificial heart valves, abnormal heart rhythms, surgery or have previously suffered from a blood clot.
Warfarin activity must be monitored carefully to ensure that an adequate and safe dose is taken each day. This is done by blood testing, to determine the international normalized ratio (INR).
If the INR is too high, there is an increased risk of abnormal bleeding (haemorrhage). If the INR is too low, it indicates that the dose is insufficient to protect against blood clots.
A simple mouth swab is all you need to avoid months of dangerous trial and error, so you can find the optimum warfarin dose for you!