Warfarin with Regorafenib Interaction Details
Brand Names Associated with Warfarin
- Coumadin®
- Jantoven®
- Warfarin
Brand Names Associated with Regorafenib
- Regorafenib
- Stivarga®
Medical Content Editor Dr. Brian Staiger, PharmD
Last updated
Dec 31, 2023
Interaction Effect
Increased warfarin exposure
Interaction Summary
Coadministration of regorafenib (a CYP2C9 inhibitor) and warfarin (a CYP2C9 substrate) resulted in at 25% increase in warfarin exposure. Use caution when coadministering regorafenib and warfarin as increased warfarin plasma concentrations and an increased risk of bleeding may occur. Monitor INR more frequently if concomitant use is required.
Severity
Major
Onset
Unspecified
Evidence
Theoretical
How To Manage Interaction
Use caution with coadministration of CYP2C9 inhibitors, such as regorafenib, with warfarin, as increased warfarin plasma concentrations and an increased risk of bleeding may occur. Monitor INR more frequently if concomitant use is required.
Mechanism Of Interaction
Inhibition of CYP2C9-mediated warfarin metabolism by regorafenib
Literature Reports
A) In a study of patients with advanced solid tumors, administration of warfarin 10 mg orally 1 week before and 2 weeks after regorafenib 160 mg once daily resulted in a 25% increase in warfarin mean AUC (N=8) .
Warfarin Overview
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Warfarin is used to prevent blood clots from forming or growing larger in your blood and blood vessels. It is prescribed for people with certain types of irregular heartbeat, people with prosthetic (replacement or mechanical) heart valves, and people who have suffered a heart attack. Warfarin is also used to treat or prevent venous thrombosis (swelling and blood clot in a vein) and pulmonary embolism (a blood clot in the lung). Warfarin is in a class of medications called anticoagulants ('blood thinners'). It works by decreasing the clotting ability of the blood.
Regorafenib Overview
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Regorafenib is used to treat colon and rectal cancer (cancer that begins in the large intestine or the rectum) that has spread to other parts of the body in people who have not been treated successfully with certain other medications. It is also used to treat gastrointestinal stromal tumors (GIST; a type of tumor that grows in the stomach, intestine [bowel], or esophagus [tube that connects the throat with the stomach]) in people who were not treated successfully with certain other medications. Regorafenib is also used to treat hepatocellular carcinoma (HCC; a type of liver cancer) in people who were previously treated with sorafenib (Nexafar). Regorafenib is in a class of medications called kinase inhibitors. It works by blocking the action of an abnormal protein that signals cancer cells to multiply. This helps to slow or stop the spread of cancer cells.
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Definitions
Severity Categories
Contraindicated
These drugs, generally, should not be used together simultaneously due to the high risk of severe adverse effects. Combining these medications can lead to dangerous health outcomes and should be strictly avoided unless otherwise instructed by your provider.
Major
This interaction could result in very serious and potentially life-threatening consequences. If you are taking this drug combination, it is very important to be under close medical supervision to minimize severe side effects and ensure your safety. It may be necessary to change a medication or dosage to prevent harm.
Moderate
This interaction has the potential to worsen your medical condition or alter the effectiveness of your treatment. It's important that you are monitored closely and you potentially may need to make adjustments in your treatment plan or drug dosage to maintain optimal health.
Minor
While this interaction is unlikely to cause significant problems, it could intensify side effects or reduce the effectiveness of one or both medications. Monitoring for changes in symptoms and your condition is recommended, and adjustments may be made if needed to manage any increased or more pronounced side effects.
Onset
Rapid: Onset of drug interaction typically occurs within 24 hours of co-administration.
Delayed: Onset of drug interaction typically occurs more than 24 hours after co-administration.
Evidence
Level of documentation of the interaction.
Established: The interaction is documented and substantiated in peer-reviewed medical literature.
Theoretical: This interaction is not fully supported by current medical evidence or well-documented sources, but it is based on known drug mechanisms, drug effects, and other relevant information.
How To Manage The Interaction
Provides a detailed discussion on how patients and clinicians can approach the identified drug interaction as well as offers guidance on what to expect and strategies to potentially mitigate the effects of the interaction. This may include recommendations on adjusting medication dosages, altering the timing of drug administration, or closely monitoring for specific symptoms.
It's important to note that all medical situations are unique, and management approaches should be tailored to individual circumstances. Patients should always consult their healthcare provider for personalized advice and guidance on managing drug interactions effectively.
Mechanism Of Interaction
The theorized or clinically determined reason (i.e., mechanism) why the drug-drug interaction occurs.
Disclaimer: The information provided on this page is for informational purposes only and should not be considered medical advice. Always consult with a qualified healthcare professional regarding your specific circumstances and medical conditions.
Where Does Our Information Come From?
Information for our drug interactions is compiled from several drug compendia, including:
The prescribing information for each drug, as published on DailyMED, is also used.
Individual drug-drug interaction detail pages contain references specific to that interaction. You can click on the reference number within brackets '[]' to see what reference was utilized.
The information posted is fact-checked by HelloPharmacist clinicians and reviewed quarterly.