Can things other than the dose of warfarin change my INR?
Definitely. This is one reason that your INR blood test needs to be measured rather frequently. Many things can alter the INR in a patient taking warfarin. Such factors include changes in your diet, vitamins, food supplements, herbal preparations, other medications (either prescription or those bought “over the counter”), change in your level of exercise, getting sick, smoking, and consuming alcohol. As mentioned above, a change in the INR may cause a big change in your risk of bleeding or blood clot formation. Therefore, you should keep you clinician informed of any of these types of changes and discuss in advance any changes you are planning in any of the above factors (such as going on a trip, starting an exercise program, trying to stop smoking, going on a new diet, taking an herbal preparation, etc.).
