Drug interactions
Mercaptopurine + Rabies vaccine
Severity: Moderate
Mercaptopurine and Rabies vaccine: 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
Mercaptopurine may reduce the antibody response to rabies vaccine, potentially leaving inadequate protection after exposure. This matters because rabies is almost always fatal once symptoms develop.
What this interaction means in plain words
Mercaptopurine and Rabies vaccine 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.
Why it happens
Immunosuppression impairs the development of an adaptive immune response to vaccine antigen.
What to do
Vaccinate when indicated, including post-exposure, and measure rabies neutralizing antibody titers afterward in immunosuppressed patients. Give immune globulin when post-exposure prophylaxis is required.
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 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 Rabies vaccine?
MediHelp rates the interaction as moderate. Mercaptopurine and Rabies vaccine 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. Mercaptopurine may reduce the antibody response to rabies vaccine, potentially leaving inadequate protection after exposure. This matters because rabies is almost always fatal once symptoms develop.
How serious is the interaction between Mercaptopurine and Rabies vaccine?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Vaccinate when indicated, including post-exposure, and measure rabies neutralizing antibody titers afterward in immunosuppressed patients. Give immune globulin when post-exposure prophylaxis is required.
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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