Mesalamine with Azathioprine Interaction Details

Brand Names Associated with Mesalamine

Brand Names Associated with Azathioprine

Medical Content Editor Dr. Brian Staiger, PharmD
Last updated Nov 25, 2023

Interaction Effect

An increased risk of blood disorders

Interaction Summary

Coadministration of azathioprine and mesalamine may result in an increased risk of blood disorders. Azathioprine is metabolized to 6-mercaptopurine, which in turn is metabolized by thiopurine methyltransferase (TPMT), converting it to the inactive 6-methylmercaptopurine metabolite . Concomitant administration of TPMT inhibitors, such as mesalamine, may led to accumulation of active metabolites, thereby causing an increased risk of myelosuppression . Therefore, caution is advised if azathioprine and mesalamine are used concomitantly . Monitor patients for signs and symptoms of myelosuppression and complete blood counts. Dosage adjustments to azathioprine or mesalamine may be necessary.

Severity

Moderate

Onset

Delayed

Evidence

Theoretical

How To Manage Interaction

Caution should be exercised with the coadministration of mesalamine and azathioprine as this may result in an increased risk of blood disorders. Monitor patients for signs and symptoms of myelosuppression and complete blood counts. Azathioprine or mesalamine dosage may need to be adjusted.

Mechanism Of Interaction

Inhibition of thiopurine methyltransferase by mesalamine

Mesalamine Overview

• Mesalamine is used to treat ulcerative colitis (a condition which causes swelling and sores in the lining of the colon [large intestine] and rectum) and also to maintain improvement of ulcerative colitis symptoms. Mesalamine is in a class of medications called anti-inflammatory agents. It works by stopping the body from producing a certain substance that may cause inflammation.

Azathioprine Overview

• Azathioprine is used with other medications to prevent transplant rejection (attack of the transplanted organ by the immune system) in people who received kidney transplants. It is also used to treat severe rheumatoid arthritis (a condition in which the body attacks its own joints, causing pain, swelling, and loss of function) when other medications and treatments have not helped. Azathioprine is in a class of medications called immunosuppressants. It works by decreasing the activity of the body's immune system so it will not attack the transplanted organ or the joints.

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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.