Known interactions between the following drugs: Coumadin, Levothyroxine

Blood clotting normally occurs in response to a cut or other types of injuries to protect the body from excessive bleeding. Many substances are involved in the clotting process including various chemicals that are produced in the body like vitamin K.. Warfarin is generally used to prevent your blood from "coagulating" or forming blood clots. Although levothyroxine does not appear to directly interact with warfarin, it may increase the breakdown of vitamin K-dependent clotting factors and make your blood much less likely to clot. When levothyroxine and warfarin are used at the same time, the anticoagulant effect of warfarin may be increased and this may increase the risk of excessive bleeding. If these drugs are taken together, your doctor may want to monitor you closely for signs of bleeding (bruising, nose bleeds, ect). Blood tests can be used to make sure that you are getting the right amount of warfarin. If you are experiencing problems, it may be necessary to adjust the dose of warfarin. Ask your healthcare provider about these drugs and this potential interaction as soon as possible.