Drug interactions
Isoniazid + Tezacaftor
Severity: Moderate
Isoniazid and Tezacaftor: 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
Tezacaftor is metabolized mainly by CYP3A4 and CYP3A5, so inhibitors can raise its exposure and the risk of adverse effects such as transaminase elevation. Isoniazid's inhibitory effect is modest, but its own hepatotoxicity adds to the concern.
What this interaction means in plain words
Isoniazid and Tezacaftor 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
Isoniazid inhibits CYP3A4, reducing tezacaftor metabolism.
What to do
Monitor liver function tests, and consider adjusting the tezacaftor/ivacaftor regimen according to product labeling for CYP3A inhibitors.
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
Frequently asked questions
Can I take Isoniazid with Tezacaftor?
MediHelp rates the interaction as moderate. Isoniazid and Tezacaftor 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. Tezacaftor is metabolized mainly by CYP3A4 and CYP3A5, so inhibitors can raise its exposure and the risk of adverse effects such as transaminase elevation. Isoniazid's inhibitory effect is modest, but its own hepatotoxicity adds to the concern.
How serious is the interaction between Isoniazid and Tezacaftor?
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 liver function tests, and consider adjusting the tezacaftor/ivacaftor regimen according to product labeling for CYP3A inhibitors.
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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