Drug interactions
Cimetidine + Imipramine
Severity: Moderate
Cimetidine and Imipramine: 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
Cimetidine can increase imipramine and desipramine concentrations, raising the risk of anticholinergic effects, sedation, hypotension and arrhythmias. The effect varies between patients.
What this interaction means in plain words
Cimetidine and Imipramine 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.
Cimetidine belongs to Gastrointestinal Tract; Imipramine belongs to Central Nervous System.
Why it happens
Cimetidine inhibits several hepatic CYP enzymes, including CYP2D6, CYP1A2 and CYP3A4, decreasing tricyclic metabolism.
What to do
Monitor for tricyclic toxicity and consider an ECG or plasma level. Reduce the imipramine dose if needed or use famotidine instead.
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 Cimetidine
- Cimetidine + Dofetilide Contraindicated
- Cimetidine + Fezolinetant Contraindicated
- Alfentanil + Cimetidine Major
- Atazanavir + Cimetidine Major
- Carmustine + Cimetidine Major
- Cimetidine + Citalopram Major
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 Cimetidine with Imipramine?
MediHelp rates the interaction as moderate. Cimetidine and Imipramine 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. Cimetidine can increase imipramine and desipramine concentrations, raising the risk of anticholinergic effects, sedation, hypotension and arrhythmias. The effect varies between patients.
How serious is the interaction between Cimetidine and Imipramine?
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 tricyclic toxicity and consider an ECG or plasma level. Reduce the imipramine dose if needed or use famotidine instead.
What other medicines interact with Cimetidine?
MediHelp also lists interactions of Cimetidine with, for example, Dofetilide, Fezolinetant, Alfentanil. The full list is on the Cimetidine page.
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