Drug interactions
Erythromycin + Ofloxacin
Severity: Moderate
Erythromycin and Ofloxacin: 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
Both drugs can prolong the QT interval, and combined use may increase the risk of ventricular arrhythmia including torsades de pointes. Ofloxacin has a lower QT liability than some other fluoroquinolones, but the risk is still additive.
What this interaction means in plain words
Erythromycin and Ofloxacin 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.
Erythromycin belongs to Anti Bacterial; Ofloxacin belongs to Anti Bacterial.
Why it happens
Additive QT prolongation through cardiac potassium channel blockade.
What to do
Avoid in patients with other QT risk factors; otherwise monitor ECG and correct electrolytes.
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 Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin Contraindicated
Other interactions of Ofloxacin
- Ofloxacin + Thioridazine Contraindicated
- Adagrasib + Ofloxacin Major
- Amiodarone + Ofloxacin Major
- Amisulpride + Ofloxacin Major
- Anagrelide + Ofloxacin Major
- Arsenic trioxide + Ofloxacin Major
Frequently asked questions
Can I take Erythromycin with Ofloxacin?
MediHelp rates the interaction as moderate. Erythromycin and Ofloxacin 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. Both drugs can prolong the QT interval, and combined use may increase the risk of ventricular arrhythmia including torsades de pointes. Ofloxacin has a lower QT liability than some other fluoroquinolones, but the risk is still additive.
How serious is the interaction between Erythromycin and Ofloxacin?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Avoid in patients with other QT risk factors; otherwise monitor ECG and correct electrolytes.
What other medicines interact with Erythromycin?
MediHelp also lists interactions of Erythromycin with, for example, Conivaptan, Dihydroergotamine intranasal, Dihydroergotamine. The full list is on the Erythromycin page.
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