Drug interactions
Cyclosporin + Letermovir
Severity: Major
Cyclosporin and Letermovir: major 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
Letermovir raises cyclosporine concentrations through CYP3A inhibition, and cyclosporine increases letermovir exposure by inhibiting OATP1B1/3. The combination can cause cyclosporine toxicity and increased letermovir adverse effects.
What this interaction means in plain words
Cyclosporin and Letermovir can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for.
Cyclosporin belongs to Miscellaneous; Letermovir belongs to Anti Virals.
Why it happens
Letermovir inhibits CYP3A and cyclosporine inhibits OATP1B1/3 transport of letermovir.
What to do
Reduce letermovir to 240 mg daily when given with cyclosporine. Monitor cyclosporine levels frequently during therapy and after letermovir is stopped.
What to ask your pharmacist
- Does the benefit of taking both outweigh the risk in my case?
- Do I need any blood test, ECG or other check while on both?
- What early warning signs should I watch for, and what should I do if they appear?
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Other interactions of Cyclosporin
- Adenovirus types 4 and 7 live + Cyclosporin Contraindicated
- Aliskiren + Cyclosporin Contraindicated
- Bcg vaccine live + Cyclosporin Contraindicated
- Bosentan + Cyclosporin Contraindicated
- Cidofovir + Cyclosporin Contraindicated
- Cyclosporin + Dengue vaccine 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 Cyclosporin with Letermovir?
MediHelp rates the interaction as major. Cyclosporin and Letermovir can interact in a way that may be serious. Using them together is sometimes necessary, but it needs a deliberate decision by the prescriber, a plan for monitoring, and clear advice on the warning signs to watch for. Letermovir raises cyclosporine concentrations through CYP3A inhibition, and cyclosporine increases letermovir exposure by inhibiting OATP1B1/3. The combination can cause cyclosporine toxicity and increased letermovir adverse effects.
How serious is the interaction between Cyclosporin and Letermovir?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Reduce letermovir to 240 mg daily when given with cyclosporine. Monitor cyclosporine levels frequently during therapy and after letermovir is stopped.
What other medicines interact with Cyclosporin?
MediHelp also lists interactions of Cyclosporin with, for example, Adenovirus types 4 and 7 live, Aliskiren, Bcg vaccine live. The full list is on the Cyclosporin page.
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