Drug interactions
Mercaptopurine + Varicella virus vaccine live
Severity: Major
Mercaptopurine and Varicella virus vaccine live: 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
In patients on mercaptopurine the live varicella vaccine may be less effective and the vaccine virus can spread, causing severe or disseminated varicella.
What this interaction means in plain words
Mercaptopurine and Varicella virus vaccine live 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.
Why it happens
Purine antimetabolite immunosuppression impairs control of live attenuated varicella virus replication.
What to do
Avoid live varicella vaccine during mercaptopurine therapy; vaccinate at least 4 weeks before starting if possible. Otherwise defer until immunosuppression has resolved, per local guidance.
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
Frequently asked questions
Can I take Mercaptopurine with Varicella virus vaccine live?
MediHelp rates the interaction as major. Mercaptopurine and Varicella virus vaccine live 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. In patients on mercaptopurine the live varicella vaccine may be less effective and the vaccine virus can spread, causing severe or disseminated varicella.
How serious is the interaction between Mercaptopurine and Varicella virus vaccine live?
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 live varicella vaccine during mercaptopurine therapy; vaccinate at least 4 weeks before starting if possible. Otherwise defer until immunosuppression has resolved, per local guidance.
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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