Drug interactions
Mercaptopurine + Tofacitinib
Severity: Major
Mercaptopurine and Tofacitinib: major interaction.
Last updated
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.
Summary
Combining a thiopurine with a JAK inhibitor increases the risk of serious infections and possibly lymphoproliferative disorders. Tofacitinib labeling advises against use with potent immunosuppressants.
What this interaction means in plain words
Mercaptopurine and Tofacitinib can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Mercaptopurine belongs to Oncology; Tofacitinib belongs to Musculoskeletal.
Why it happens
Additive immunosuppression through purine antimetabolite effects and JAK inhibition.
What to do
Avoid the combination when an alternative exists; otherwise monitor for infection and check blood counts regularly.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Mercaptopurine
- Adenovirus types 4 and 7 live + Mercaptopurine Contraindicated
- Azathioprine + Mercaptopurine Contraindicated
- Bcg vaccine live + Mercaptopurine Contraindicated
- Febuxostat + Mercaptopurine Contraindicated
- Influenza virus vaccine quadrivalent intranasal + Mercaptopurine Contraindicated
- Mercaptopurine + Smallpox vaccine live Contraindicated
Other interactions of Tofacitinib
- Baricitinib + Tofacitinib Contraindicated
- Cladribine + Tofacitinib Contraindicated
- Tofacitinib + Upadacitinib Contraindicated
- Abatacept + Tofacitinib Major
- Anti-thymocyte + Tofacitinib Major
- Antithymocyte globulin equine + Tofacitinib Major
Frequently asked questions
Can I take Mercaptopurine with Tofacitinib?
MediHelp rates the interaction as major. Mercaptopurine and Tofacitinib can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Combining a thiopurine with a JAK inhibitor increases the risk of serious infections and possibly lymphoproliferative disorders. Tofacitinib labeling advises against use with potent immunosuppressants.
How serious is the interaction between Mercaptopurine and Tofacitinib?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid the combination when an alternative exists; otherwise monitor for infection and check blood counts regularly.
What other medicines interact with Mercaptopurine?
MediHelp also lists interactions of Mercaptopurine with, for example, Adenovirus types 4 and 7 live, Azathioprine, Bcg vaccine live. The full list is on the Mercaptopurine page.
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