Infliximab with Warfarin Interaction Details

Brand Names Associated with Infliximab

Brand Names Associated with Warfarin

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Dec 03, 2023

Interaction Effect

Decreased warfarin plasma concentrations

Interaction Summary

In states of chronic inflammation, the formation of CYP450 enzymes is suppressed by increased levels of cytokines such as tumor necrosis factor (TNF) alpha. Upon administration of a TNF alpha antagonist, such as infliximab or infliximab biosimilar products, the formation of CYP450 enzymes could be normalized. If infliximab or infliximab biosimilar products are initiated or discontinued in a patient being treated with a CYP450 substrate with a narrow therapeutic index, such as warfarin, monitor the effects of warfarin and adjust the dose as needed.

Severity

Major

Onset

Unspecified

Evidence

Theoretical

How To Manage Interaction

If infliximab or infliximab biosimilar products are initiated in a patient being treated with a CYP450 substrate with a narrow therapeutic index, such as warfarin, the effectiveness may be reduced due to a possible reduction of warfarin concentration. Monitor for effectiveness of warfarin and adjust the dose as needed. Furthermore, when infliximab or infliximab biosimilar products are discontinued, the concentration of warfarin may increase and potentially result in toxicity. Monitor for toxicity and consider a dose reduction of warfarin when infliximab or infliximab biosimilar products are discontinued.

Mechanism Of Interaction

Increase in CYP450-mediated warfarin metabolism

Infliximab Overview

• Infliximab injection products are used to relieve the symptoms of certain autoimmune disorders (conditions in which the immune system attacks healthy parts of the body and causes pain, swelling, and damage) including:

  • rheumatoid arthritis (a condition in which the body attacks its own joints, causing pain, swelling, and loss of function) that is also being treated with methotrexate (Rheumatrex, Trexall),

  • Crohn's disease (a condition in which the body attacks the lining of the digestive tract, causing pain, diarrhea, weight loss, and fever) in adults and children 6 years of age or older that has not improved when treated with other medications,

  • ulcerative colitis (condition that causes swelling and sores in the lining of the large intestine) in adults and children 6 years of age or older that has not improved when treated with other medications,

  • ankylosing spondylitis (a condition in which the body attacks the joints of the spine and other areas causing pain and joint damage),

  • plaque psoriasis (a skin disease in which red, scaly patches form on some areas of the body) in adults when other treatments are less appropriate,

  • and psoriatic arthritis (a condition that causes joint pain and swelling and scales on the skin).

• Infliximab injection products are in a class of medications called tumor necrosis factor-alpha (TNF-alpha) inhibitors. They work by blocking the action of TNF-alpha, a substance in the body that causes inflammation.

Warfarin Overview

• 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.

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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:

• Gold Standard Drug Database
• Micromedex
• Lexicomp
• DrugBank

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.