Mercaptopurine and Mesalazine: Drug Interaction Guide

Quick answer: This combination requires caution. Mercaptopurine and Mesalazine can be used together with adjustments and monitoring.

Interaction severity: Moderate — caution required

How Mercaptopurine interacts with Mesalazine

Mesalazine inhibits thiopurine S-methyltransferase (TPMT), reducing 6-mercaptopurine inactivation and increasing risk of myelosuppression.

What you should do

Monitor full blood count every 1-2 weeks for the first 2 months of combination therapy. Reduce thiopurine dose if cytopenia develops.

Key facts

Severity

Moderate — caution required

Mechanism

Mesalazine inhibits thiopurine S-methyltransferase (TPMT), reducing 6-mercaptopurine inactivation and increasing risk of...

Action

Monitor full blood count every 1-2 weeks for the first 2 months of combination therapy. Reduce thiopurine dose if cytope...

Important medical disclaimer: This page provides educational information about drug interactions for general reference. It is not a substitute for professional medical advice, diagnosis, or treatment. Always discuss your specific medications with a qualified healthcare provider before starting, stopping, or changing any treatment. About our editorial team.

Frequently asked questions

Can I take Mercaptopurine and Mesalazine together?

With caution. Monitor full blood count every 1-2 weeks for the first 2 months of combination therapy. Reduce thiopurine dose if cytopenia develops.

What is the severity of this interaction?

The interaction between Mercaptopurine and Mesalazine is classified as Moderate — caution required. Mesalazine inhibits thiopurine S-methyltransferase (TPMT), reducing 6-mercaptopurine inactivation and increasing risk of myelosuppression.

What should I do if I'm prescribed both?

Monitor full blood count every 1-2 weeks for the first 2 months of combination therapy. Reduce thiopurine dose if cytopenia develops. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

Last reviewed: by iMedic Medical Editorial Team. Our editorial process.