Coumadin (warfarin) is an anticoagulant medication used to prevent and treat the formation of blood clots. It is also known by its generic name as warfarin. Its function of preventing blood clots is different that the antiplatelet kinds of medication which are also anticoagulants. Instead of reducing the bloods viscosity Coumadin alters the proteins and enzymes that are essential for proper blood clotting through its elimination of vitamin K from the body. The altered proteins and enzymes lose their ability to form proper blood clots which in turn is how Coumadin functions as a anticoagulant. In addition to avoiding foods high in vitamin K it is also recommended to avoid combining warfarin and alcohol in large amounts while undergoing treatment.
Effects on the liver
One of the reasons to not combine alcohol and Coumadin (warfarin) is it can put additional stress upon the liver. Once ingested alcohol is absorbed into the bloodstream through the stomach lining and the intestines. Once into the bloodstream the alcohol is processed in the liver. The liver is responsible for processing the alcohol into manageable compounds that the body can either use or remove easily. When too much alcohol is ingested the liver cannot process all of the alcohol at once and toxicity developed in the liver causing damage. Repeating this for an extended period of time will lead to liver damage. Coumadin is also processed by the liver and can be hard on the liver if taken for extended periods of time. So combining the two can increase the severity and speed at which the liver is damaged. However, this is usually only an issue in those who already have liver problems or are unacceptable to liver problems.
Alcohol as an antiplatelet
Another reason alcohol and warfarin should avoid being combined in large amounts is due to alcohol's antiplatelet effects. Most doctors advise that those without previous liver problems or a family history of liver problems are fine having a couple of drink every now and again without experiencing adverse effects. However, in high enough amounts alcohol can act as an antiplatelet. This means that it thins the blood. When this effect is combined with Coumadin it increases the risk of uncontrollable bleeding from minor injuries. It also increases the risk of bruising appearing at random or internal bleeding. If after drinking alcohol while undergoing Coumadin treatment and you find blood in your stools or if you vomit blood you should probably see a doctor immediately as this is indication of internal bleeding.
Coumadin and alcohol effects on blood tests
When undergoing treatment with Coumadin (warfarin) patients are required to give samples of blood to be tested every so often to ensure that the dosage is correct and is not too high or too low. These tests results are refereed to as INR ranges. Drinking alcohol regularly or in large amounts can effect your INR ranges in your tests indicating that alcohol is messing with the function of the medication. If you drink regularly the amounts of warfarin given to you will have to be adjusted more often. This can be a hassle and each dose adjustment is inherently risky. For this reason while undergoing treatment with Coumadin it is recommended to avoid alcohol for the most part, though a drink here and there shouldn't have any severe negative effects.