Drug interactions
Trazodone + Trimethoprim
Severity: Moderate
Trazodone 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
Trazodone can prolong the QT interval, and trimethoprim has been associated with QT prolongation and hyperkalemia in some reports. Combined use may add to arrhythmia risk in susceptible patients.
What this interaction means in plain words
Trazodone 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.
Trazodone belongs to Central Nervous System; Trimethoprim belongs to Anti Bacterial.
Why it happens
Additive QT prolongation, with possible electrolyte effects.
What to do
Check ECG and potassium in patients with cardiac disease, electrolyte abnormalities or other QT-prolonging drugs.
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 Trazodone
- Arsenic trioxide + Trazodone Contraindicated
- Ibutilide + Trazodone Contraindicated
- Isocarboxazid + Trazodone Contraindicated
- Levoketoconazole + Trazodone Contraindicated
- Methylene blue + Trazodone Contraindicated
- Phenelzine + Trazodone Contraindicated
Other interactions of Trimethoprim
Frequently asked questions
Can I take Trazodone with Trimethoprim?
MediHelp rates the interaction as moderate. Trazodone 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. Trazodone can prolong the QT interval, and trimethoprim has been associated with QT prolongation and hyperkalemia in some reports. Combined use may add to arrhythmia risk in susceptible patients.
How serious is the interaction between Trazodone 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, electrolyte abnormalities or other QT-prolonging drugs.
What other medicines interact with Trazodone?
MediHelp also lists interactions of Trazodone with, for example, Arsenic trioxide, Ibutilide, Isocarboxazid. The full list is on the Trazodone page.
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