College of Pharmacy
HelixTalk Episode #121 - But Wait, There’s More! Unusual Warfarin Interactions
Date posted: November 3, 2020, 6:00 am
In this episode, we will discuss some of the interesting and unusual warfarin interactions such as acetaminophen, alcohol, agents with antiplatelet properties, non-green vitamin K foods, and CBD/THC.
Key Concepts
- Patients should always be educated to consult their pharmacist and/or PCP whenever there is a change in any medications (OTC, prescription, herbals, supplements, etc.) as well lifestyle (diet, weight loss, alcohol use, THC use, etc.)
- Closer monitoring of INR is required in most instances of warfarin drug interactions; some interactions do not modify the INR but can still increase the risk of bleeding/bruising
- A warfarin interaction rarely means "contraindication". Warfarin dose adjustment may address the INR fluctuations but in some cases stopping the use of such products becomes necessary.
References
- Foods with Vitamin K. http://www.coumadin.bmscustomerconnect.com/servlet/servlet.FileDownload?file=00Pi000000bxvTFEAY
- Coumadin Package Insert. http://www.coumadin.bmscustomerconnect.com/servlet/servlet.FileDownload?file=00Pi000000bxvTFEAY