Drug interactions
Isoniazid + Itraconazole
Severity: Minor
Isoniazid and Itraconazole: 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
The legacy direction of this interaction is unclear; isoniazid is not a recognized enzyme inducer. Reduced itraconazole exposure is mostly reported with rifampicin, which is often co-administered with isoniazid. Isoniazid alone is unlikely to alter itraconazole levels meaningfully.
What this interaction means in plain words
Isoniazid and Itraconazole have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Isoniazid belongs to Anti Bacterial; Itraconazole belongs to Anti Fungals.
Why it happens
No established mechanism for isoniazid alone; rifampicin induction explains reductions in combination regimens.
What to do
If rifampicin is part of the regimen, avoid itraconazole or monitor itraconazole levels. Otherwise no action is needed beyond liver function monitoring.
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?
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Other interactions of Isoniazid
Other interactions of Itraconazole
- Alfuzosin + Itraconazole Contraindicated
- Alprazolam + Itraconazole Contraindicated
- Avanafil + Itraconazole Contraindicated
- Conivaptan + Itraconazole Contraindicated
- Dihydroergotamine intranasal + Itraconazole Contraindicated
- Dihydroergotamine + Itraconazole Contraindicated
Frequently asked questions
Can I take Isoniazid with Itraconazole?
MediHelp rates the interaction as minor. Isoniazid and Itraconazole have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. The legacy direction of this interaction is unclear; isoniazid is not a recognized enzyme inducer. Reduced itraconazole exposure is mostly reported with rifampicin, which is often co-administered with isoniazid. Isoniazid alone is unlikely to alter itraconazole levels meaningfully.
How serious is the interaction between Isoniazid and Itraconazole?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: If rifampicin is part of the regimen, avoid itraconazole or monitor itraconazole levels. Otherwise no action is needed beyond liver function monitoring.
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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