Drug interactions
Codeine + Letermovir
Severity: Minor
Codeine and Letermovir: minor 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 raise exposure to codeine through the minor norcodeine pathway, potentially shifting metabolism toward morphine. The clinical effect is uncertain, but opioid adverse effects could increase.
What this interaction means in plain words
Codeine and Letermovir have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Codeine belongs to Musculoskeletal; Letermovir belongs to Anti Virals.
Why it happens
Letermovir inhibits CYP3A4, altering codeine metabolism; codeine is mainly glucuronidated and activated by CYP2D6, so the effect is likely small.
What to do
No empiric dose change is needed; monitor for sedation and respiratory depression during co-therapy.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
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Other interactions of Codeine
- Alvimopan + Codeine Contraindicated
- Codeine + Isocarboxazid Contraindicated
- Codeine + Olanzapine / samidorphan Contraindicated
- Codeine + Phenelzine Contraindicated
- Codeine + Tranylcypromine Contraindicated
- Alfentanil + Codeine 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 Codeine with Letermovir?
MediHelp rates the interaction as minor. Codeine and Letermovir have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Letermovir inhibits CYP3A4 and may raise exposure to codeine through the minor norcodeine pathway, potentially shifting metabolism toward morphine. The clinical effect is uncertain, but opioid adverse effects could increase.
How serious is the interaction between Codeine and Letermovir?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: No empiric dose change is needed; monitor for sedation and respiratory depression during co-therapy.
What other medicines interact with Codeine?
MediHelp also lists interactions of Codeine with, for example, Alvimopan, Isocarboxazid, Olanzapine / samidorphan. The full list is on the Codeine page.
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