Drug interactions
Clarithromycin + Letermovir
Severity: Moderate
Clarithromycin and Letermovir: 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 may modestly raise letermovir exposure through inhibition of hepatic uptake and metabolism. Letermovir in turn inhibits CYP3A4, which may raise clarithromycin levels. The effects are usually modest.
What this interaction means in plain words
Clarithromycin and Letermovir 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; Letermovir belongs to Anti Virals.
Why it happens
Inhibition of OATP1B1/3 and CYP3A-mediated clearance of letermovir, with reciprocal CYP3A inhibition by letermovir.
What to do
No empirical dose change is required. Monitor for letermovir adverse effects such as nausea and for clarithromycin toxicity, including QT prolongation.
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 Clarithromycin
- Astemizole + Clarithromycin Contraindicated
- Avanafil + Clarithromycin Contraindicated
- Cisapride + Clarithromycin Contraindicated
- Clarithromycin + Colchicine Contraindicated
- Clarithromycin + Conivaptan Contraindicated
- Clarithromycin + Dihydroergotamine Contraindicated
Other interactions of Letermovir
- Ergotamine + Letermovir Contraindicated
- Letermovir + Pimozide Contraindicated
- Apalutamide + Letermovir Major
- Atorvastatin + Letermovir Major
- Carbamazepine + Letermovir Major
- Colchicine + Letermovir Major
Frequently asked questions
Can I take Clarithromycin with Letermovir?
MediHelp rates the interaction as moderate. Clarithromycin and Letermovir 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 may modestly raise letermovir exposure through inhibition of hepatic uptake and metabolism. Letermovir in turn inhibits CYP3A4, which may raise clarithromycin levels. The effects are usually modest.
How serious is the interaction between Clarithromycin and Letermovir?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No empirical dose change is required. Monitor for letermovir adverse effects such as nausea and for clarithromycin toxicity, including QT prolongation.
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.
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