 Don't be afraid to discuss your concerns and ask questions of your clinician. He or she can help make sure you take this medicine safely. One thing to remember is that you will need to schedule a regular blood test to be sure you are not getting too much or too little medicine. The blood tests let the doctor know how much medicine you need. Your doctor will order a blood test called INR. INR stands for International Normalized Ratio. The INR will tell your doctor the amount of time it takes for your blood to clot and whether or not she might need to adjust the dose you are taking. If your INR is too high or too low, your doctor may change the amount of medicine that you take until your INR is within a range that's right for you. Your clinician or health plan will tell you where to go to get your blood tested. It is very important to have your blood checked as often as your clinician tells you to. It is the only way he or she can tell how much medicine you need. Like most medicines, blood thinner pills can have side effects. Some of these may include bruising easily or having your gums bleed from brushing your teeth. If you find any unusual bleeding, let your clinician know right away. You should try to be careful in your daily activities and avoid injury as much as possible. Just by chance, you do injure yourself whether it be from a fall or hard bump to the head. Call your clinician right away.