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Drug interactions

Hepatitis a / b vaccine + Mercaptopurine

Severity: Minor

Hepatitis a / b vaccine and Mercaptopurine: minor 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 can lower antibody responses to this inactivated vaccine, so protection may be incomplete. There is no risk of vaccine-strain infection.

What this interaction means in plain words

Hepatitis a / b vaccine and Mercaptopurine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.

Evidence level: Moderate

Why it happens

Immunosuppression reduces the B- and T-cell response to vaccine antigens.

What to do

Vaccinate as scheduled and check anti-HBs and anti-HAV titres afterwards. Revaccinate or give a higher dose if the response is inadequate.

What to ask your pharmacist

  • Is there anything I should notice while taking both?
  • Do I need to tell my doctor at the next visit?

Bring a full list of your medicines, including over-the-counter products, supplements and herbal remedies, to every pharmacy visit.

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Frequently asked questions

Can I take Hepatitis a / b vaccine with Mercaptopurine?

MediHelp rates the interaction as minor. Hepatitis a / b vaccine and Mercaptopurine have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Mercaptopurine can lower antibody responses to this inactivated vaccine, so protection may be incomplete. There is no risk of vaccine-strain infection.

How serious is the interaction between Hepatitis a / b vaccine and Mercaptopurine?

MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Vaccinate as scheduled and check anti-HBs and anti-HAV titres afterwards. Revaccinate or give a higher dose if the response is inadequate.

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.

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.

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