1 interaction was found for the drugs you selected.
WARFARIN SODIUM in Coumadin
may interact with LEVONORGESTREL in Plan B
Although the cause of this potential interaction is not clearly understood, levonorgestrel may increase the anticoagulant effect of warfarin. Warfarin is generally used to prevent your blood from "coagulating" or forming blood clots. When levonorgestrel and warfarin are used at the same time, your blood may be much less likely to clot and this may increase the risk of excessive bleeding. Because only a limited amount of information is available on this potential interaction, more clinical studies will be needed to determine the safety of using these drugs together. If these drugs are taken together, your doctor may want to monitor you closely when therapy with levonorgestrel is either started or stopped. 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. Discuss this potential interaction with your healthcare provider at your next appointment, or sooner if you think you are having problems.
This interaction is poorly documented and is considered moderate in severity.