Increased bleeding with cuts is possible and should be understood before looking to order Coumadin online. The most common side effects reported with generic Coumadin are nausea, vomiting, loss of appetite, or stomach pain. INR (International Normalized Ratio) tests are required weekly to monitor the levels of this drug in the blood. The risk for bleeding can continue for up to 1 week, so dosage might change throughout therapy, as recommended by your local personal doctor. Inform him or her promptly if unusual pain, swelling, nosebleeds, or chest pain occur. Also if blood is visible in the urine, vomit, or stools. Prolonged or heavier periods are possible.