Drug interactions
Fentanyl + Letermovir
Severity: Moderate
Fentanyl 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
Letermovir inhibits CYP3A4 and may increase fentanyl concentrations. This raises the risk of prolonged sedation and respiratory depression.
What this interaction means in plain words
Fentanyl 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.
Fentanyl belongs to Musculoskeletal; Letermovir belongs to Anti Virals.
Why it happens
Letermovir inhibits CYP3A4, reducing the clearance of fentanyl.
What to do
Monitor respiratory status and sedation and reduce the fentanyl dose if needed. Take extra care with continuous or transdermal fentanyl.
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 Fentanyl
- Alvimopan + Fentanyl Contraindicated
- Fentanyl + Isocarboxazid Contraindicated
- Fentanyl + Olanzapine / samidorphan Contraindicated
- Fentanyl + Phenelzine Contraindicated
- Fentanyl + Tranylcypromine Contraindicated
- Alfentanil + Fentanyl Major
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 Fentanyl with Letermovir?
MediHelp rates the interaction as moderate. Fentanyl 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. Letermovir inhibits CYP3A4 and may increase fentanyl concentrations. This raises the risk of prolonged sedation and respiratory depression.
How serious is the interaction between Fentanyl 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: Monitor respiratory status and sedation and reduce the fentanyl dose if needed. Take extra care with continuous or transdermal fentanyl.
What other medicines interact with Fentanyl?
MediHelp also lists interactions of Fentanyl with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Fentanyl page.
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