Drug interactions
Imipramine + Trimethoprim
Severity: Moderate
Imipramine and Trimethoprim: 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
Imipramine can prolong the QT interval, and trimethoprim has been associated with QT prolongation and arrhythmia in isolated reports. Trimethoprim can also cause hyperkalemia, which may add to cardiac risk.
What this interaction means in plain words
Imipramine and Trimethoprim 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; Trimethoprim belongs to Anti Bacterial.
Why it happens
Possible additive QT prolongation; trimethoprim's contribution is not well established.
What to do
Check ECG and potassium in patients with cardiac disease, renal impairment or other QT-prolonging drugs. Choose an alternative antibiotic if QTc is prolonged.
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 Imipramine
- Dronedarone + Imipramine Contraindicated
- Imipramine + Isocarboxazid Contraindicated
- Imipramine + Phenelzine Contraindicated
- Imipramine + Pimozide Contraindicated
- Imipramine + Rasagiline Contraindicated
- Imipramine + Safinamide Contraindicated
Other interactions of Trimethoprim
Frequently asked questions
Can I take Imipramine with Trimethoprim?
MediHelp rates the interaction as moderate. Imipramine and Trimethoprim 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 can prolong the QT interval, and trimethoprim has been associated with QT prolongation and arrhythmia in isolated reports. Trimethoprim can also cause hyperkalemia, which may add to cardiac risk.
How serious is the interaction between Imipramine and Trimethoprim?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Check ECG and potassium in patients with cardiac disease, renal impairment or other QT-prolonging drugs. Choose an alternative antibiotic if QTc is prolonged.
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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