Achieving the correct warfarin dosage can be difficult but is extremely important. Warfarin must be monitored to ensure it is working effectively and being used safely. The dose may also need to be adjusted based on a patient’s diet and current medications. Warfarin therapy may be prescribed for patients with certain types of irregular heartbeat, blood clots in the legs or lungs, and patients who have certain medical device implants such as artificial heart valves.Ī patient’s warfarin dose depends on many factors, including the patient’s age, overall health and genetic makeup. Warfarin (also known by the brand names Coumadin and Jantoven) is a blood thinner prescribed to prevent and treat blood clots. The FDA wants to ensure patients and health care providers use these devices safely. INR test meters and test strips are medical devices regulated by the U.S. The INR is used by patients and physicians to determine if warfarin dosing is appropriate. The meter reads the test strip, measures how long it takes the blood to clot, and provides the result based on a standardized calculation in the form of the International Normalized Ratio, or INR. A test strip is inserted into the meter, and then a lancet (a medical pricking needle) is used to obtain blood which is applied to the test strip. The meter has a screen that displays results, and an opening for meter-specific test strips. change the amount of fruit and vegetables you eat) then the amount of warfarin you need may also change.An INR test meter is a portable, battery-operated meter, used to monitor patient response to warfarin. If you change your vitamin K intake significantly (e.g. It is not essential to change your diet but it is helpful to have a healthy diet that is generally stable in the amount of fruit and vegetables you eat. The amount of warfarin you require will be altered depending on how much vitamin K (fruit and vegetables) you have in your diet. Should I change my diet when on warfarin? It will take a week or two and a few blood tests to find out how much warfarin you will need. 1mg per day) but other people need much more warfarin (greater than 10mg per day). Some people need only a little amount of warfarin (e.g. What dose of warfarin should I take?ĭifferent people require different doses of warfarin and this will depend on the level of blood thinning required. There are a number of pathology collection centres around Melbourne and INR blood tests can be done each of these collection centres.

How are blood tests performed?Ī number of pathology companies can check the warfarin level (e.g Melbourne Pathology, Healthscope and Dorevitch). Once you have “stable” levels and your dose is known, blood tests are usually done once every few weeks.

This will help find out how much warfarin you require. Once warfarin is started, you will need frequent blood tests – usually every second day. Sometimes patients require “thinner” blood levels with INR levels of 2.5 – 3.5. Most people on warfarin require blood thinning to a level of an INR 2.0 – 3.0. Someone with “normal” blood thinning has an INR of 1.0. How are blood thinning levels measured?īlood thinning levels are measured with a blood test called the INR (international normalized ratio). That is why the level of blood thinning needs to be checked regularly. If the blood is too thin there is a risk of bleeding. Warfarin acts against Vitamin K and stops the blood clotting proteins from working properly and thins the blood. We get Vitamin K from fruit and vegetables. These proteins need a vitamin to work properly this vitamin is called Vitamin K. Warfarin thins the blood by stopping blood clotting proteins from working. Warfarin is given to either prevent blood clots developing or to stop clots that have already developed from getting larger. Warfarin is a type of anticoagulant medication taken in tablet form used to thin the blood.

Pt inr normal range on coumadin