Warfarin/Aprepitant Interactions

This information is generalized and not intended as specific medical advice. Consult your healthcare professional before taking or discontinuing any drug or commencing any course of treatment.

Medical warning:

Serious. These medicines may interact and cause very harmful effects. Contact your healthcare professional (e.g. doctor or pharmacist) for more information.

How the interaction occurs:

Aprepitant may speed up how quickly your liver processes warfarin.

What might happen:

About 7-10 days after you start taking aprepitant, your warfarin may not work as well.

What you should do about this interaction:

Let your healthcare professionals (e.g. doctor or pharmacist) know that you are taking these medicines, or if you have taken aprepitant in the previous two weeks. Your doctor may want to check your bleeding times more often during the 2 weeks after you take aprepitant. The dose of your warfarin may need to be adjusted during this time.Your healthcare professionals may already be aware of this interaction and may be monitoring you for it. Do not start, stop, or change the dosage of any medicine before checking with them first.

  • 1.Emend (aprepitant) Australian prescribing information. MSD April 5, 2004.
  • 2.Emend (aprepitant) UK summary of product characteristics. Merck Sharp & Dohme Limited January 10. 2005.
  • 3.Emend (aprepitant) US prescribing information. Merck & Co., Inc. September, 2019.

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CONDITIONS OF USE: The information in this database is intended to supplement, not substitute for, the expertise and judgment of healthcare professionals. The information is not intended to cover all possible uses, directions, precautions, drug interactions or adverse effects, nor should it be construed to indicate that use of a particular drug is safe, appropriate or effective for you or anyone else. A healthcare professional should be consulted before taking any drug, changing any diet or commencing or discontinuing any course of treatment.