These are medications to prevent the clotting of the blood. Various groups of drugs are available with different modes and duration of action.
They are used in patients who have suffered heart attacks, strokes or developed blood clots in the veins or lungs.
They may have to be stopped before an operation or their action reveresed with a different medication or blood clotting products.
The administration of shorter-acting anti-coagulants may be necessary before and after an operation if the patient is at a high risk of developing blood clots, a stroke or a heart attack.