Drug interactions
allopurinol + azathioprine
For healthcare professionals — reference only. This page is a brief summary, not medical advice and not a substitute for official labeling or clinical judgement. Always verify before prescribing or dispensing.
Overview
Severe myelosuppression unless AZA dose reduced.
Mechanism of action
XO inhibition → ↑ 6-MP.
Clinical management
Reduce AZA dose to 25–33% or avoid; monitor counts.
Drug reference
References
Frequently asked questions
Can I take allopurinol with azathioprine?
The interaction is rated: Major. Severe myelosuppression unless AZA dose reduced.
How serious is the interaction between allopurinol and azathioprine?
The interaction is rated: Major. Evidence level: High.
How is the interaction between allopurinol and azathioprine managed?
Reduce AZA dose to 25–33% or avoid; monitor counts.
Why do allopurinol and azathioprine interact?
XO inhibition → ↑ 6-MP.
Full monographs, dosing and an interaction checker in the MediHelp app
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