Drug interactions
Isoniazid + Zanubrutinib
Severity: Moderate
Isoniazid and Zanubrutinib: 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
Zanubrutinib is a CYP3A4 substrate, and inhibition of this enzyme can increase its exposure and the risk of adverse effects such as bleeding, cytopenias and infections. Isoniazid inhibits CYP3A4 only weakly to moderately, so the effect is likely small.
What this interaction means in plain words
Isoniazid and Zanubrutinib 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.
Isoniazid belongs to Anti Bacterial; Zanubrutinib belongs to Oncology.
Why it happens
Isoniazid inhibits CYP3A4, reducing the first-pass and systemic metabolism of zanubrutinib.
What to do
Monitor blood counts and for bleeding or infection; reduce zanubrutinib to 80 mg twice daily if isoniazid is considered a clinically relevant CYP3A4 inhibitor, and restore the dose after stopping it.
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 Isoniazid
Other interactions of Zanubrutinib
Frequently asked questions
Can I take Isoniazid with Zanubrutinib?
MediHelp rates the interaction as moderate. Isoniazid and Zanubrutinib 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. Zanubrutinib is a CYP3A4 substrate, and inhibition of this enzyme can increase its exposure and the risk of adverse effects such as bleeding, cytopenias and infections. Isoniazid inhibits CYP3A4 only weakly to moderately, so the effect is likely small.
How serious is the interaction between Isoniazid and Zanubrutinib?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood counts and for bleeding or infection; reduce zanubrutinib to 80 mg twice daily if isoniazid is considered a clinically relevant CYP3A4 inhibitor, and restore the dose after stopping it.
What other medicines interact with Isoniazid?
MediHelp also lists interactions of Isoniazid with, for example, Bacillus calmette-guerin substrain tice, Benzhydrocodone / acetaminophen, Carbamazepine. The full list is on the Isoniazid page.
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