Drug interactions
Imipramine + Isoniazid
Severity: Moderate
Imipramine and Isoniazid: 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
Isoniazid may increase imipramine levels through CYP inhibition and has weak MAO inhibitory activity, so tricyclic toxicity and serotonergic effects are possible. Reports of significant reactions are limited, though anticholinergic effects, arrhythmia and agitation can occur.
What this interaction means in plain words
Imipramine and Isoniazid 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.
Imipramine belongs to Central Nervous System; Isoniazid belongs to Anti Bacterial.
Why it happens
Isoniazid inhibits CYP2C19/other CYP pathways and weakly inhibits MAO, raising imipramine exposure and serotonergic activity.
What to do
Monitor for anticholinergic effects, serotonin toxicity and ECG changes. Consider measuring imipramine levels and reducing the dose if needed.
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 Imipramine
- Dronedarone + Imipramine Contraindicated
- Imipramine + Isocarboxazid Contraindicated
- Imipramine + Phenelzine Contraindicated
- Imipramine + Pimozide Contraindicated
- Imipramine + Rasagiline Contraindicated
- Imipramine + Safinamide Contraindicated
Frequently asked questions
Can I take Imipramine with Isoniazid?
MediHelp rates the interaction as moderate. Imipramine and Isoniazid 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 may increase imipramine levels through CYP inhibition and has weak MAO inhibitory activity, so tricyclic toxicity and serotonergic effects are possible. Reports of significant reactions are limited, though anticholinergic effects, arrhythmia and agitation can occur.
How serious is the interaction between Imipramine and Isoniazid?
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 for anticholinergic effects, serotonin toxicity and ECG changes. Consider measuring imipramine levels and reducing the dose if needed.
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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