Drug interactions
Leflunomide + Mechlorethamine
Severity: Major
Leflunomide and Mechlorethamine: 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
Mechlorethamine is a cytotoxic alkylating agent that causes myelosuppression, and leflunomide can also cause bone marrow suppression and immunosuppression. Together they raise the risk of cytopenias and serious infection.
What this interaction means in plain words
Leflunomide and Mechlorethamine 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.
Leflunomide belongs to Musculoskeletal; Mechlorethamine belongs to Oncology.
Why it happens
Additive myelosuppressive and immunosuppressive effects.
What to do
Monitor complete blood counts and liver tests at least monthly, and avoid a leflunomide loading dose. Consider accelerated elimination with cholestyramine if severe toxicity occurs.
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 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
Other interactions of Mechlorethamine
Frequently asked questions
Can I take Leflunomide with Mechlorethamine?
MediHelp rates the interaction as major. Leflunomide and Mechlorethamine 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. Mechlorethamine is a cytotoxic alkylating agent that causes myelosuppression, and leflunomide can also cause bone marrow suppression and immunosuppression. Together they raise the risk of cytopenias and serious infection.
How serious is the interaction between Leflunomide and Mechlorethamine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor complete blood counts and liver tests at least monthly, and avoid a leflunomide loading dose. Consider accelerated elimination with cholestyramine if severe toxicity occurs.
What other medicines interact with Leflunomide?
MediHelp also lists interactions of Leflunomide with, for example, Bcg vaccine live, Influenza virus vaccine quadrivalent intranasal, Measles mumps and rubella vaccine live. The full list is on the Leflunomide page.
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