Warfarin Drug Interactions


4.7 out of 5 (27 Reviews)



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Expiration Date

28 Feb 2026

Last Reviewed

1 Mar 2023

Estimated Time To Finish

90 Minutes

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Activity Description

Warfarin has FDA approval for the prophylaxis and treatment of venous thrombosis and its complications, such as a pulmonary embolus. It is also indicated to prevent thromboembolic complications associated with conditions such as atrial fibrillation, cardiac valve replacement, and inherited genetic factors like C and S protein deficiency or Factor V Leiden. Additionally, warfarin is FDA approved as an adjunct to reduce the risk of myocardial infarction (MI) and other thromboembolic events in high-risk patients. However, warfarin falls in the narrow therapeutic index drug category and is subject to numerous interactions. This activity outlines the indications, mechanism of action, interactions, significant adverse effects, contraindications, toxicity, and warfarin monitoring so providers can direct patient therapy where anticoagulation is indicated as part of the interprofessional team.

Target Audience

This activity has been designed to meet the educational needs of physicians.

Learning Objectives

At the conclusion of this activity, the learner will be better able to:

  • Identify the mechanism of action of warfarin.
  • Review the agents that can either increase or decrease the anticoagulant effect of warfarin.
  • Summarize the target INR levels for warfarin therapy based on conditions that affect INR targets.
  • Describe the importance of collaboration and coordination among the interprofessional team and how it can enhance patient care with warfarin therapy in conjunction with the patient's entire medication regimen to improve patient outcomes for patients with conditions where anticoagulation is indicated.


StatPearls requires everyone who influences the content of an educational activity to disclose relevant financial relationships with ineligible companies that have occurred within the past 24 months. All relevant conflict(s) of interest have been mitigated. Hover over contributor names for financial disclosures. None of the planners of this educational activity have any relevant financial relationships to disclose.

COMMERCIAL SUPPORT: This activity has received NO commercial support.

Continuing Education Accreditation Information

This activity has been planned and implemented in accordance with the accreditation requirements and policies of the Accreditation Council for Continuing Medical Education (ACCME) through the joint providership of the Quillen College of Medicine, East Tennessee State University, and StatPearls, LLC. The Quillen College of Medicine, East Tennessee State University is accredited by the ACCME to provide continuing medical education for physicians.

Quillen College of Medicine, East Tennessee State University designates this activity for a maximum of 1.50 AMA PRA Category 1 CreditsTM. Physicians should only claim credit commensurate with the extent of their participation in the activity.

This activity is reported to the following Maintenance of Certification (MOC) boards:
American Board of Anesthesiology
  • General Operative Anesthesia
American Board of Internal Medicine
  • Cardiovascular Disease
  • Geriatric Medicine
  • Hospital Medicine
  • Internal Medicine
American Board of Pediatrics
  • General Pediatrics
  • Pediatric Cardiology
American Board of Surgery
  • General Surgery

Instructions for Credit

  1. Register for the activity and create a StatPearls login.     
  2. Review the target audience, learning objectives, and disclosure information.
  3. Study the educational content in the activity.
  4. Choose the best answer to each activity test question. To receive credit, you must pass the test questions with a minimum score of 100%.
  5. Complete the post-activity assessment.
  6. Obtain a certificate.

For information on the applicability and acceptance of continuing education credit for this activity, please consult your professional licensing board.


Faculty may discuss investigational products or off-label uses of products regulated by the US Food and Drug Administration. Readers should verify all information before employing any therapies described in this educational activity.

The information provided for this activity is for continuing education purposes only and is not meant to substitute for the independent medical/clinical judgment of a healthcare provider relative to diagnostic and treatment options of a specific patient’s medical condition. The information presented does not necessarily reflect the views of StatPearls or any commercial supporters of educational activities on statpearls.com. StatPearls specifically disclaims responsibility for any adverse consequences resulting directly or indirectly from information in the course, for undetected error, or through a participant's misunderstanding of the content.

Cancellation Policy: Cancellations must be received in writing and a money-back guarantee is provided if not completely satisfied.

  • StatPearlsand and Quillen College of Medicine, East Tennessee State University reserve the right to cancel any course due to unforeseen circumstances. StatPearls andQuillen College of Medicine, East Tennessee State University will not be responsible for other expenses incurred by the participant in the unlikely event that the program is canceled.

Medium or Media Used:

  • Computer Requirements: Internet Access
  • E-mail Address

Equal Opportunity

  • StatPearls andQuillen College of Medicine, East Tennessee State University are Equal Opportunity/Affirmative Action/Equal Access Institutions. 


Media Usage Rights

The contributors and editors of StatPearls have attested that all associated media (images and video) have been legally cleared for use with this activity.  All copyrights are reserved.


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    Expand this course to include more drugs and icrease CEUs to 3.

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