Information and Service for people on Warfarin Therapy

What is Warfarin? Warfarin is a drug which interferes with the action of Vitamin K, the essential vitamin required for the production of blood clotting substances called coagulation factors. Warfarin inactivates these coagulation factors and is therefore an anticoagulant or 'blood thinning' drug.

Who takes Warfarin? A large number of people now take Warfarin to reduce the chance of blood clots occurring or recurring. It is used in the treatment of deep vein thrombosis, pulmonary embolism, atrial fibrillation, prosthetic heart valves, myocardial infarction and other diseases.

Why does Warfarin therapy need to be monitored? Unlike many other drugs, there is no simple way to estimate the correct dose of Warfarin for any one person. A blood test called the INR (International Normalized Ratio) will indicate when the drug's effect is in the therapeutic range. This is the range in which the drug is most effective and least harmful.

If the INR is too low, the drug's anticoagulant activity is too low and may not prevent blood clotting. If the INR is too high, 'bleeding' may occur. Signs of 'bleeding' may include nose bleeds, bleeding gums or cuts which bleed for a longer time than normal. If the INR is maintained in the therapeutic range, Warfarin is a safe and effective drug treatment.

After an initial period of stabilisation, the majority of people will require a blood test once a month to monitor their Warfarin therapy.

Unfortunately, a number of factors can affect Warfarin's anticoagulant action. Starting or stopping other medications or herbal remedies, a change in diet, exercise, or forgetting to take tablets may increase or decrease the effect of Warfarin and therefore the INR. Warfarin therapy requires close monitoring to maintain safe and effective treatment.

What is Warfarin Care? Your doctor has been offering a service identical to Warfarin Care for many years. Warfarin Care is a service provided by Northern  Pathology Townsville to doctors whose patients are taking Warfarin, and to the patients themselves. We will perform regular blood tests to establish when Warfarin has achieved its therapeutic effect. This is the lowest possible dose which gives the most beneficial result.

Northern  Pathology Townsville will then inform you when the next test should be carried out. We will also advise you if any change in the dose of Warfarin is required. Warfarin Care will ensure that your doctor is made aware of all results and changes in doses.

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