Drug interactions
Diazepam + Fluvoxamine
Severity: Major
Diazepam and Fluvoxamine: major interaction.
Last updated Sources: US FDA label
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
Fluvoxamine inhibits CYP2C19 and CYP3A4 and can markedly raise diazepam concentrations. This can produce pronounced and prolonged sedation and impaired coordination.
What this interaction means in plain words
Diazepam and Fluvoxamine 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.
Diazepam belongs to Musculoskeletal; Fluvoxamine belongs to Central Nervous System.
Why it happens
Fluvoxamine inhibits CYP2C19 and CYP3A4, reducing diazepam metabolism.
What to do
Reduce the diazepam dose and monitor for oversedation; consider lorazepam, which is not oxidatively metabolized.
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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References
Other interactions of Diazepam
Other interactions of Fluvoxamine
- Agomelatine + Fluvoxamine Contraindicated
- Alosetron + Fluvoxamine Contraindicated
- Fezolinetant + Fluvoxamine Contraindicated
- Fluvoxamine + Isocarboxazid Contraindicated
- Fluvoxamine + Mavacamten Contraindicated
- Fluvoxamine + Methylene blue Contraindicated
Frequently asked questions
Can I take Diazepam with Fluvoxamine?
MediHelp rates the interaction as major. Diazepam and Fluvoxamine 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. Fluvoxamine inhibits CYP2C19 and CYP3A4 and can markedly raise diazepam concentrations. This can produce pronounced and prolonged sedation and impaired coordination.
How serious is the interaction between Diazepam and Fluvoxamine?
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 the diazepam dose and monitor for oversedation; consider lorazepam, which is not oxidatively metabolized.
What other medicines interact with Diazepam?
MediHelp also lists interactions of Diazepam with, for example, Calcium / magnesium / potassium / sodium oxybates, Alfentanil, Alprazolam. The full list is on the Diazepam page.
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