Warfarin, commonly known as the brand Coumadin, is a prescription anticoagulant drug. Licorice is commonly known as a flavoring for candy and beverages, but it is also an herbal remedy claimed to be useful for various conditions. Licorice may interact with Coumadin and cause problems if you combine these two substances. Consult your health care provider before taking licorice as an herbal remedy or eating large amounts of licorice if you take any type of medication.
Coumadin Function
Doctors prescribe Coumadin to prevent blood clots from developing or growing larger in patients at risk for these occurrences. A certain level of blood-clotting ability is essential for preventing and stopping bleeding, but harmful blood clots can lead to a stroke or heart attack. You may have heard Coumadin referred to as a blood thinner, but it doesn't actually thin your blood. Instead, it lengthens the time it takes for your blood to clot.
Interactions
While taking Coumadin, you need regular blood testing to make sure your clotting time is within certain levels. Your doctor may adjust your dosage after these tests. Numerous medications and herbs and even some foods can lead to excessive bleeding when combined with warfarin. Another potential problem with Coumadin therapy involves substances that decrease the effectiveness of the medication. Information is conflicting on how licorice interacts with Coumadin.
Reduced Effectiveness
As your body breaks down Coumadin to eliminate it, licorice may increase the rate of this breakdown, which would reduce the effectiveness of your medication, explains MedlinePlus. This website lists the interaction between licorice and Coumadin as a major one, because lowering the effectiveness of Coumadin could increase your risk of dangerous blood clots.
Increased Effectiveness
A study published in January 2010 in the "World Journal of Gastrointestinal Surgery" found a possible link between eating black licorice and developing increased anticoagulant activity. Licorice has shown anticoagulant effects in laboratory studies, but clinical evidence of this effect has been lacking, according to the authors. This case study involved a woman who developed gastrointestinal bleeding after eating large amounts of black licorice while also taking warfarin.
