Drug interactions
Azathioprine + Leflunomide
Severity: Major
Azathioprine and Leflunomide: 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
Both drugs suppress lymphocyte proliferation and together raise the risk of myelosuppression, hepatotoxicity and infection. Pancytopenia has been described with leflunomide combined with other immunosuppressive or marrow-toxic agents.
What this interaction means in plain words
Azathioprine and Leflunomide 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.
Azathioprine belongs to Gastrointestinal Tract; Leflunomide belongs to Musculoskeletal.
Why it happens
Additive immunosuppressive and myelosuppressive effects from purine synthesis inhibition and pyrimidine synthesis (DHODH) inhibition.
What to do
Avoid the combination where possible. If used, monitor complete blood count and liver enzymes frequently and watch for signs of infection.
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 Azathioprine
- Adenovirus types 4 and 7 live + Azathioprine Contraindicated
- Azathioprine + Bcg vaccine live Contraindicated
- Azathioprine + Febuxostat Contraindicated
- Azathioprine + Influenza virus vaccine quadrivalent intranasal Contraindicated
- Azathioprine + Measles mumps and rubella vaccine Contraindicated
- Azathioprine + Measles mumps and rubella vaccine live Contraindicated
Other interactions of Leflunomide
- Bcg vaccine live + Leflunomide Contraindicated
- Influenza virus vaccine quadrivalent intranasal + Leflunomide Contraindicated
- Leflunomide + Measles mumps and rubella vaccine live Contraindicated
- Leflunomide + Measles mumps rubella and varicella vaccine live Contraindicated
- Leflunomide + Measles vaccine Contraindicated
- Leflunomide + Smallpox vaccine live Contraindicated
Frequently asked questions
Can I take Azathioprine with Leflunomide?
MediHelp rates the interaction as major. Azathioprine and Leflunomide 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. Both drugs suppress lymphocyte proliferation and together raise the risk of myelosuppression, hepatotoxicity and infection. Pancytopenia has been described with leflunomide combined with other immunosuppressive or marrow-toxic agents.
How serious is the interaction between Azathioprine and Leflunomide?
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 where possible. If used, monitor complete blood count and liver enzymes frequently and watch for signs of infection.
What other medicines interact with Azathioprine?
MediHelp also lists interactions of Azathioprine with, for example, Adenovirus types 4 and 7 live, Bcg vaccine live, Febuxostat. The full list is on the Azathioprine page.
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