Important anticoagulant precautions

Vitamin K and aspirin can have a critical impact on blood-thinning meds

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Blood-thinning medications can be impacted by vitamin K and aspirin-containing products.

The formation of a clot in the body is a complex process that involves multiple substances called “clotting factors.” Clotting factors are proteins made in the liver. Some of these proteins, however, cannot be created without vitamin K, a common vitamin found in:

  • cabbage
  • cauliflower
  • spinach
  • other leafy green vegetables

Because anticoagulants such as warfarin (also known as Coumadin® or Jantoven®) slow clot formation by competing with vitamin K, it’s important to maintain a consistent daily intake of vitamin K and to be aware of anticoagulant precautions. Each person’s warfarin dosage is related to the amount of vitamin K in his or her body. If you overload your system with vitamin K, you override the effectiveness of the blood-thinning medication.

Aspirin – it’s more prevalent than you might think

If you are taking warfarin, do not take aspirin unless prescribed by your healthcare provider, and never exceed more than 325 milligrams per day.

Also, be aware of over-the-counter medications that contain aspirin or aspirin-like ingredients, including Excedrin, Alka-Seltzer, Bayer, Bufferin, Ecotrin, Empirin, Nyquil and Pepto Bismol (liquid and tablets). Check with your physician or pharmacist to make sure the medication is safe.

Other natural products that have aspirin-like characteristics include gingko, ginseng and glucosamine. Spices such as cayenne pepper, ginger, garlic, paprika, turmeric, licorice and peppermint, as well as fruits such as raisins, cranberries and grapes, may have a similar effect. As part of a regular dietary plan, these products are safe, but high doses of these ingredients could heighten a person’s risk of bleeding if combined with anticoagulation medication.

U-M’s Anticoagulation Service recognized for excellence

The University of Michigan Anticoagulation Service was recently recognized as an “Anticoagulation Center of Excellence,” illustrating its strong commitment to providing the highest level of patient care.

The Anticoagulation Centers of Excellence program helps healthcare professionals achieve the best possible outcomes for patients on anticoagulant medications. The program offers a roadmap to consistent, sustainable excellence in patient care.

Take the next step:

Elizabeth Renner150x150Elizabeth Renner graduated from the University of Michigan College of Pharmacy in 2009 and completed a pharmacy practice residency at Toledo Hospital. In addition to board certifications in pharmacotherapy and ambulatory care pharmacy, she recently became a certified anticoagulation care provider. She is committed to helping patients reach their health goals by ensuring safe and effective use of medications.


Frankel-informal-vertical-sigThe University of Michigan Samuel and Jean Frankel Cardiovascular Center is the top-ranked heart and heart surgery program among Michigan hospitals. To learn more, visit our website at umcvc.org.