Azathioprine and Trimethoprim Sulfamethoxazole: Drug Interaction Guide

Quick answer: This combination requires caution. Azathioprine and Trimethoprim Sulfamethoxazole can be used together with adjustments and monitoring.

Interaction severity: Moderate — caution required

How Azathioprine interacts with Trimethoprim Sulfamethoxazole

Both drugs can suppress bone marrow; trimethoprim also has antifolate activity, increasing risk of leukopenia, thrombocytopenia, and pancytopenia.

What you should do

Use only when clearly indicated, monitor complete blood count closely, and counsel patients to report fever, bruising, or sore throat promptly.

Key facts

Severity

Moderate — caution required

Mechanism

Both drugs can suppress bone marrow; trimethoprim also has antifolate activity, increasing risk of leukopenia, thrombocy...

Action

Use only when clearly indicated, monitor complete blood count closely, and counsel patients to report fever, bruising, o...

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 Azathioprine and Trimethoprim Sulfamethoxazole together?

With caution. Use only when clearly indicated, monitor complete blood count closely, and counsel patients to report fever, bruising, or sore throat promptly.

What is the severity of this interaction?

The interaction between Azathioprine and Trimethoprim Sulfamethoxazole is classified as Moderate — caution required. Both drugs can suppress bone marrow; trimethoprim also has antifolate activity, increasing risk of leukopenia, thrombocytopenia, and pancytopenia.

What should I do if I'm prescribed both?

Use only when clearly indicated, monitor complete blood count closely, and counsel patients to report fever, bruising, or sore throat promptly. Always consult your prescribing clinician — do not stop or change medications without medical guidance.

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