Drug interactions
Caffeine + Letermovir
Severity: Minor
Caffeine 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 may raise caffeine exposure, potentially intensifying stimulant effects such as insomnia, tremor and tachycardia. Letermovir is thought to inhibit CYP2C9 and CYP2C19 and induce them, with effects on CYP1A2 less clear.
What this interaction means in plain words
Caffeine 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.
Caffeine belongs to Miscellaneous; Letermovir belongs to Anti Virals.
Why it happens
Possible modest reduction in caffeine metabolism by letermovir; the exact enzyme involvement is not firmly established.
What to do
No routine dose change is required; advise reducing caffeine intake if stimulant symptoms appear.
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 Caffeine
- Caffeine + Ephedrine Major
- Caffeine + Fezolinetant Major
- Caffeine + Methylenedioxymethamphetamine Major
- Caffeine + Selegiline transdermal Major
- Adenosine + Caffeine Moderate
- Benzphetamine + Caffeine Moderate
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 Caffeine with Letermovir?
MediHelp rates the interaction as minor. Caffeine 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 may raise caffeine exposure, potentially intensifying stimulant effects such as insomnia, tremor and tachycardia. Letermovir is thought to inhibit CYP2C9 and CYP2C19 and induce them, with effects on CYP1A2 less clear.
How serious is the interaction between Caffeine 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 routine dose change is required; advise reducing caffeine intake if stimulant symptoms appear.
What other medicines interact with Caffeine?
MediHelp also lists interactions of Caffeine with, for example, Ephedrine, Fezolinetant, Methylenedioxymethamphetamine. The full list is on the Caffeine page.
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