Drug interactions
Isoniazid + Nortriptyline
Severity: Moderate
Isoniazid and Nortriptyline: 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's weak MAO inhibition may add to nortriptyline's monoaminergic effects, theoretically increasing serotonin toxicity risk. Clinical reports are rare.
What this interaction means in plain words
Isoniazid and Nortriptyline 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; Nortriptyline belongs to Central Nervous System.
Why it happens
Additive monoaminergic effect from weak MAO inhibition and reuptake inhibition.
What to do
Monitor for signs of serotonin toxicity and tricyclic adverse effects. Stop one agent if toxicity occurs.
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 Nortriptyline
- Disopyramide + Nortriptyline Contraindicated
- Dofetilide + Nortriptyline Contraindicated
- Dronedarone + Nortriptyline Contraindicated
- Ibutilide + Nortriptyline Contraindicated
- Isocarboxazid + Nortriptyline Contraindicated
- Methylene blue + Nortriptyline Contraindicated
Frequently asked questions
Can I take Isoniazid with Nortriptyline?
MediHelp rates the interaction as moderate. Isoniazid and Nortriptyline 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's weak MAO inhibition may add to nortriptyline's monoaminergic effects, theoretically increasing serotonin toxicity risk. Clinical reports are rare.
How serious is the interaction between Isoniazid and Nortriptyline?
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 signs of serotonin toxicity and tricyclic adverse effects. Stop one agent if toxicity occurs.
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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