If you are at risk for conditions which may cause life-threatening blood clots, your doctor may prescribe an anticoagulant such as Coumadin to help thin your blood. Coumadin helps prevent heart attacks and strokes, as well as blood clots in the lungs or legs. While extremely effective, the medication comes with serious potential side effects, especially if not taken or monitored properly.
Common Side Effects
Coumadin may produce side effects that are generally considered more annoying than dangerous. These include stomach pain or cramping, fatigue, nausea, vomiting, dizziness and hair loss. You may also experience gas or bloating, weakness, diarrhea, changes in your taste and a constant feeling of being cold. If these do not subside, or become too bothersome, speak to your doctor.
Serious Side Effects
While some side effects can be expected, others are serious and less common. These side effects should be reported immediately to your physician. They include changes or discoloration of your skin (anywhere on your body), pain in your back or sides, bruising easily, an inability to stop bleeding and blood in your stools. Your doctor should also be called promptly if you have a sudden problem with speech, a sudden loss of coordination or suddenly become confused. Purple toes and fingers, blood in your urine, nosebleeds and coughing up blood are other side effects your doctor should be made aware of.
Overdose
It is natural to forget a dose of your medication every now and again. However, in an attempt to make up for your missed dose, you may overdose on your medication. An overdose of Coumadin, according to Drugs.com, will cause symptoms such as broken blood vessels, blood in your urine and/or stools, easy bruising and heavy menstrual cycles.
Considerations
Avoid taking the following medications together with Coumadin: aspirin, ibuprofen, acetaminophen, celecoxib, indomethacin, naproxen, diclofenac and piroxicam. According to Drugs.com, the aforementioned drugs, combined with Coumadin, could result in severe bleeding in your intestines or stomach.
In addition, alcohol consumption could increase some of Coumadin's side effects.


