Drug interactions
Leflunomide + Ustekinumab
Severity: Moderate
Leflunomide and Ustekinumab: moderate 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 agents suppress immune function, so using them together may increase the risk of serious infections. Leflunomide has a very long active metabolite half-life, so its effect persists for a long time after stopping.
What this interaction means in plain words
Leflunomide and Ustekinumab can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken.
Leflunomide belongs to Musculoskeletal; Ustekinumab belongs to Gastrointestinal Tract.
Why it happens
Additive immunosuppression through IL-12/23 blockade (ustekinumab) and inhibition of pyrimidine synthesis in lymphocytes (leflunomide).
What to do
Screen for latent tuberculosis and active infection before combining, and monitor for signs of infection and blood counts and liver tests during therapy. Consider whether both agents are truly needed.
What to ask your pharmacist
- Should I take them at different times of day?
- Does the dose of either medicine need to change?
- Is there anything I should avoid, such as alcohol or certain foods, while on both?
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Other interactions of Ustekinumab
- Bcg vaccine live + Ustekinumab Contraindicated
- Typhoid vaccine live + Ustekinumab Contraindicated
- Adalimumab + Ustekinumab Major
- Adenovirus types 4 and 7 live + Ustekinumab Major
- Alefacept + Ustekinumab Major
- Anakinra + Ustekinumab Major
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 Leflunomide with Ustekinumab?
MediHelp rates the interaction as moderate. Leflunomide and Ustekinumab can affect each other. The combination is often manageable, but it may need a change of dose, a change of timing, or extra checks while both are taken. Both agents suppress immune function, so using them together may increase the risk of serious infections. Leflunomide has a very long active metabolite half-life, so its effect persists for a long time after stopping.
How serious is the interaction between Leflunomide and Ustekinumab?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Screen for latent tuberculosis and active infection before combining, and monitor for signs of infection and blood counts and liver tests during therapy. Consider whether both agents are truly needed.
What other medicines interact with Ustekinumab?
MediHelp also lists interactions of Ustekinumab with, for example, Bcg vaccine live, Typhoid vaccine live, Adalimumab. The full list is on the Ustekinumab page.
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