Drug interactions
Clarithromycin + Olanzapine
Severity: Moderate
Clarithromycin 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
Clarithromycin is a known QT-prolonging agent and olanzapine has a small, uncommon QT effect, so the combination adds modest arrhythmic risk. Olanzapine metabolism is mainly via CYP1A2 and UGT, so a pharmacokinetic effect is minimal.
What this interaction means in plain words
Clarithromycin 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.
Clarithromycin belongs to Anti Bacterial; Olanzapine belongs to Central Nervous System.
Why it happens
Possible additive QT prolongation; no meaningful pharmacokinetic interaction is established.
What to do
Check baseline QTc and electrolytes in patients with additional risk factors and monitor during therapy. Consider an alternative antibiotic where risk is high.
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?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Clarithromycin and Olanzapine, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
Other interactions of Olanzapine
Frequently asked questions
Can I take Clarithromycin with Olanzapine?
MediHelp rates the interaction as moderate. Clarithromycin 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. Clarithromycin is a known QT-prolonging agent and olanzapine has a small, uncommon QT effect, so the combination adds modest arrhythmic risk. Olanzapine metabolism is mainly via CYP1A2 and UGT, so a pharmacokinetic effect is minimal.
How serious is the interaction between Clarithromycin 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: Check baseline QTc and electrolytes in patients with additional risk factors and monitor during therapy. Consider an alternative antibiotic where risk is high.
What other medicines interact with Clarithromycin?
MediHelp also lists interactions of Clarithromycin with, for example, Astemizole, Avanafil, Cisapride. The full list is on the Clarithromycin page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
