Drug interactions
Azithromycin + Formoterol
Severity: Moderate
Azithromycin and Formoterol: 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
Azithromycin can prolong the QT interval and formoterol may add to arrhythmic risk through hypokalemia and sympathetic stimulation. The risk is greatest in patients with existing QT risk factors.
What this interaction means in plain words
Azithromycin and Formoterol 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.
Azithromycin belongs to Anti Bacterial; Formoterol belongs to Respiratory.
Why it happens
Additive effects on cardiac repolarization, with beta-2 agonist induced hypokalemia.
What to do
Check potassium and magnesium and consider an ECG in patients with cardiac disease or other QT-prolonging drugs. Consider an alternative antibiotic in high-risk patients.
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 Formoterol
- Adagrasib + Formoterol Major
- Amiodarone + Formoterol Major
- Amisulpride + Formoterol Major
- Amitriptyline + Formoterol Major
- Amoxapine + Formoterol Major
- Arformoterol + Formoterol Major
Other interactions of Azithromycin
- Azithromycin + Cisapride Contraindicated
- Azithromycin + Domperidone Contraindicated
- Azithromycin + Dronedarone Contraindicated
- Azithromycin + Pimozide Contraindicated
- Azithromycin + Piperaquine Contraindicated
- Azithromycin + Thioridazine Contraindicated
Frequently asked questions
Can I take Azithromycin with Formoterol?
MediHelp rates the interaction as moderate. Azithromycin and Formoterol 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. Azithromycin can prolong the QT interval and formoterol may add to arrhythmic risk through hypokalemia and sympathetic stimulation. The risk is greatest in patients with existing QT risk factors.
How serious is the interaction between Azithromycin and Formoterol?
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 potassium and magnesium and consider an ECG in patients with cardiac disease or other QT-prolonging drugs. Consider an alternative antibiotic in high-risk patients.
What other medicines interact with Formoterol?
MediHelp also lists interactions of Formoterol with, for example, Adagrasib, Amiodarone, Amisulpride. The full list is on the Formoterol page.
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