Drug interactions
Fluvoxamine + Ritonavir
Severity: Moderate
Fluvoxamine and Ritonavir: 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
Ritonavir is a potent CYP3A4 inhibitor and also affects CYP2D6, and may increase fluvoxamine exposure, while fluvoxamine's effect on ritonavir is small. Elevated fluvoxamine can cause nausea, sedation and serotonergic effects, and ritonavir carries a QT risk.
What this interaction means in plain words
Fluvoxamine and Ritonavir 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.
Fluvoxamine belongs to Central Nervous System; Ritonavir belongs to Anti Virals.
Why it happens
Mutual pharmacokinetic effects via CYP inhibition, with ritonavir being the more potent inhibitor.
What to do
Monitor for fluvoxamine adverse effects and adjust its dose as needed; consider an ECG in patients with QT risk factors.
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 Fluvoxamine
- Agomelatine + Fluvoxamine Contraindicated
- Alosetron + Fluvoxamine Contraindicated
- Fezolinetant + Fluvoxamine Contraindicated
- Fluvoxamine + Isocarboxazid Contraindicated
- Fluvoxamine + Mavacamten Contraindicated
- Fluvoxamine + Methylene blue Contraindicated
Other interactions of Ritonavir
- Alfuzosin + Ritonavir Contraindicated
- Amiodarone + Ritonavir Contraindicated
- Avanafil + Ritonavir Contraindicated
- Colchicine + Ritonavir Contraindicated
- Dronedarone + Ritonavir Contraindicated
- Eletriptan + Ritonavir Contraindicated
Frequently asked questions
Can I take Fluvoxamine with Ritonavir?
MediHelp rates the interaction as moderate. Fluvoxamine and Ritonavir 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. Ritonavir is a potent CYP3A4 inhibitor and also affects CYP2D6, and may increase fluvoxamine exposure, while fluvoxamine's effect on ritonavir is small. Elevated fluvoxamine can cause nausea, sedation and serotonergic effects, and ritonavir carries a QT risk.
How serious is the interaction between Fluvoxamine and Ritonavir?
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 for fluvoxamine adverse effects and adjust its dose as needed; consider an ECG in patients with QT risk factors.
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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