Drug interactions
Amiodarone + Trimethoprim
Severity: Moderate
Amiodarone 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
Trimethoprim, particularly as co-trimoxazole, has been linked to QT prolongation and hyperkalemia, which may add to amiodarone's proarrhythmic potential. The clinical risk is real but generally lower than with other QT-prolonging drugs.
What this interaction means in plain words
Amiodarone 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.
Amiodarone belongs to Cardiovascular; Trimethoprim belongs to Anti Bacterial.
Why it happens
Additive QT prolongation, with trimethoprim-induced hyperkalemia possibly contributing to arrhythmia risk.
What to do
Obtain a baseline ECG and monitor potassium and magnesium during therapy. Prefer an alternative antibiotic in patients with other QT risk factors.
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 Amiodarone
- Amiodarone + Amisulpride Contraindicated
- Amiodarone + Arsenic trioxide Contraindicated
- Amiodarone + Dofetilide Contraindicated
- Amiodarone + Dronedarone Contraindicated
- Amiodarone + Droperidol Contraindicated
- Amiodarone + Eliglustat Contraindicated
Other interactions of Trimethoprim
Frequently asked questions
Can I take Amiodarone with Trimethoprim?
MediHelp rates the interaction as moderate. Amiodarone 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. Trimethoprim, particularly as co-trimoxazole, has been linked to QT prolongation and hyperkalemia, which may add to amiodarone's proarrhythmic potential. The clinical risk is real but generally lower than with other QT-prolonging drugs.
How serious is the interaction between Amiodarone 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: Obtain a baseline ECG and monitor potassium and magnesium during therapy. Prefer an alternative antibiotic in patients with other QT risk factors.
What other medicines interact with Amiodarone?
MediHelp also lists interactions of Amiodarone with, for example, Amisulpride, Arsenic trioxide, Dofetilide. The full list is on the Amiodarone page.
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