Drug interactions
Azathioprine + Lomustine
Severity: Major
Azathioprine and Lomustine: major interaction.
Last updated Sources: UK SmPC
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
Lomustine causes delayed and cumulative myelosuppression, and azathioprine adds immunosuppression and marrow toxicity. Together they increase the risk of severe cytopenias and serious infections.
What this interaction means in plain words
Azathioprine and Lomustine 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; Lomustine belongs to Oncology.
Why it happens
Additive myelosuppressive and immunosuppressive effects.
What to do
Monitor complete blood counts frequently, including during the weeks after lomustine dosing, and reduce azathioprine dose if cytopenias develop.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Azathioprine and Lomustine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
References
- Azathioprine 25mg Film-Coated Tablets - SmPC sections 4.3/4.5 (class statement: cytostatic agents; "Where possible, concomitant administration of cytostatic agents, or medicinal products which may have a myelosuppressive effect, such as penicillamine, should b") — electronic medicines compendium (UK SmPC)
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 Lomustine
- Adenovirus types 4 and 7 live + Lomustine Contraindicated
- Bcg vaccine live + Lomustine Contraindicated
- Influenza virus vaccine quadrivalent intranasal + Lomustine Contraindicated
- Lomustine + Measles mumps and rubella vaccine Contraindicated
- Lomustine + Measles mumps and rubella vaccine live Contraindicated
- Lomustine + Measles mumps rubella and varicella vaccine live Contraindicated
Frequently asked questions
Can I take Azathioprine with Lomustine?
MediHelp rates the interaction as major. Azathioprine and Lomustine 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. Lomustine causes delayed and cumulative myelosuppression, and azathioprine adds immunosuppression and marrow toxicity. Together they increase the risk of severe cytopenias and serious infections.
How serious is the interaction between Azathioprine and Lomustine?
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 frequently, including during the weeks after lomustine dosing, and reduce azathioprine dose if cytopenias develop.
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.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
