Drug interactions
Duloxetine + Fluvoxamine
Severity: Major
Duloxetine 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 strongly inhibits CYP1A2, the main metabolic route of duloxetine, markedly raising duloxetine exposure. Together with additive serotonergic activity this increases the risk of serotonin syndrome and duloxetine adverse effects.
What this interaction means in plain words
Duloxetine 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.
Duloxetine belongs to Central Nervous System; Fluvoxamine belongs to Central Nervous System.
Why it happens
Strong CYP1A2 inhibition by fluvoxamine reduces duloxetine clearance, plus additive serotonergic effects.
What to do
Avoid the combination; choose an alternative antidepressant. If unavoidable, use a reduced duloxetine dose and monitor for serotonin toxicity.
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 Fluvoxamine
- Agomelatine + Fluvoxamine Contraindicated
- Alosetron + Fluvoxamine Contraindicated
- Fezolinetant + Fluvoxamine Contraindicated
- Fluvoxamine + Isocarboxazid Contraindicated
- Fluvoxamine + Mavacamten Contraindicated
- Fluvoxamine + Methylene blue Contraindicated
Other interactions of Duloxetine
- Duloxetine + Isocarboxazid Contraindicated
- Duloxetine + Linezolid Contraindicated
- Duloxetine + Methylene blue Contraindicated
- Duloxetine + Phenelzine Contraindicated
- Duloxetine + Procarbazine Contraindicated
- Duloxetine + Rasagiline Contraindicated
Frequently asked questions
Can I take Duloxetine with Fluvoxamine?
MediHelp rates the interaction as major. Duloxetine 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 strongly inhibits CYP1A2, the main metabolic route of duloxetine, markedly raising duloxetine exposure. Together with additive serotonergic activity this increases the risk of serotonin syndrome and duloxetine adverse effects.
How serious is the interaction between Duloxetine 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: Avoid the combination; choose an alternative antidepressant. If unavoidable, use a reduced duloxetine dose and monitor for serotonin toxicity.
What other medicines interact with Fluvoxamine?
MediHelp also lists interactions of Fluvoxamine with, for example, Agomelatine, Alosetron, Fezolinetant. The full list is on the Fluvoxamine page.
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