Before using this medication, tell your doctor or pharmacist your medical history, especially of blood disorders (such as anemia, hemophilia), bleeding problems (such as bleeding of the stomach/intestines, bleeding in the brain), blood vessel disorders (such as aneurysms), recent major injury/surgery, kidney disease, liver disease, alcohol use, mental/mood disorders(including memory problems), frequent falls/injuries. Warfarin can cause very serious (possibly fatal) bleeding. This is more likely to occur when you first start taking this medication or if you take too much warfarin. To decrease your risk for bleeding, your doctor or other health care provider will monitor you closely and check your lab results (INR test) to make sure you are not taking too much warfarin. Keep all medical and laboratory appointments. Tell your doctor right away if you notice any signs of serious bleeding. See also Side Effects section. This medication can cause heavy bleeding. To lower the chance of getting cut, bruised, or injured, use great caution with sharp objects like safety razors and nail cutters. Use an electric razor when shaving and a soft toothbrush when brushing your teeth. Avoid activities such as contact sports. If you fall or injure yourself, especially if you hit your head, call your doctor right away. Your doctor may need to check you. Very small amounts of this medication may pass into breast milk but is unlikely to harm a nursing infant. Consult your doctor before breast-feeding. Some products that may interact with this drug include capecitabine, imatinib, mifepristone. Aspirin, aspirin-like drugs (salicylates), and nonsteroidal anti-inflammatory drugs (NSAIDs such as ibuprofen, naproxen, celecoxib) may have effects similar to warfarin. These drugs may increase the risk of bleeding problems if taken during treatment with warfarin. Carefully check all prescription/nonprescription product labels (including drugs applied to the skin such as pain-relieving creams) since the products may contain NSAIDs or salicylates. Talk to your doctor about using a different medication (such as acetaminophen) to treat pain/fever. Low-dose aspirin and related drugs (such as clopidogrel, ticlopidine) should be continued if prescribed by your doctor for specific medical reasons such as heart attack or stroke prevention. Consult your doctor or pharmacist for more details. Many herbal products interact with warfarin. Tell your doctor before taking any herbal products, especially bromelains, coenzyme Q10, danshen, dong quai, fenugreek, garlic, ginkgo biloba, ginseng, and St. John's wort, among others. This drug is known to cause issues during pregnancy, therefore please do not take this drug if you are pregnant.