Drug interactions
Imipramine + Nortriptyline
Severity: Major
Imipramine and Nortriptyline: major 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
Both are tricyclic antidepressants, so combining them duplicates therapy and adds cardiac conduction slowing, QT prolongation, anticholinergic burden, sedation and seizure risk. Both are CYP2D6 substrates and compete for metabolism, and imipramine is converted to desipramine, so toxicity may result.
What this interaction means in plain words
Imipramine and Nortriptyline can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Imipramine belongs to Central Nervous System; Nortriptyline belongs to Central Nervous System.
Why it happens
Duplicate tricyclic pharmacology with additive cardiotoxic, anticholinergic and serotonergic effects and shared CYP2D6 metabolism.
What to do
Avoid concurrent use and use one tricyclic only; if switching, taper one before starting the other with ECG monitoring.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Imipramine
- Dronedarone + Imipramine Contraindicated
- Imipramine + Isocarboxazid Contraindicated
- Imipramine + Phenelzine Contraindicated
- Imipramine + Pimozide Contraindicated
- Imipramine + Rasagiline Contraindicated
- Imipramine + Safinamide Contraindicated
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 Imipramine with Nortriptyline?
MediHelp rates the interaction as major. Imipramine and Nortriptyline can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Both are tricyclic antidepressants, so combining them duplicates therapy and adds cardiac conduction slowing, QT prolongation, anticholinergic burden, sedation and seizure risk. Both are CYP2D6 substrates and compete for metabolism, and imipramine is converted to desipramine, so toxicity may result.
How serious is the interaction between Imipramine and Nortriptyline?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid concurrent use and use one tricyclic only; if switching, taper one before starting the other with ECG monitoring.
What other medicines interact with Imipramine?
MediHelp also lists interactions of Imipramine with, for example, Dronedarone, Isocarboxazid, Phenelzine. The full list is on the Imipramine page.
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