Drug interactions
Erythromycin + Olanzapine
Severity: Moderate
Erythromycin and Olanzapine: 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, though olanzapine has a relatively small effect. Combined use may add to arrhythmia risk in susceptible patients.
What this interaction means in plain words
Erythromycin and Olanzapine 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; Olanzapine belongs to Central Nervous System.
Why it happens
Additive QT prolongation through cardiac potassium channel effects.
What to do
Obtain a baseline ECG and correct potassium and magnesium in patients with risk factors. Consider an alternative antibiotic if QTc is already 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 Erythromycin
- Conivaptan + Erythromycin Contraindicated
- Dihydroergotamine intranasal + Erythromycin Contraindicated
- Dihydroergotamine + Erythromycin Contraindicated
- Domperidone + Erythromycin Contraindicated
- Dronedarone + Erythromycin Contraindicated
- Droperidol + Erythromycin Contraindicated
Other interactions of Olanzapine
Frequently asked questions
Can I take Erythromycin with Olanzapine?
MediHelp rates the interaction as moderate. Erythromycin and Olanzapine 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, though olanzapine has a relatively small effect. Combined use may add to arrhythmia risk in susceptible patients.
How serious is the interaction between Erythromycin and Olanzapine?
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 correct potassium and magnesium in patients with risk factors. Consider an alternative antibiotic if QTc is already prolonged.
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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