Drug interactions
Fluvoxamine + Lonafarnib
Severity: Major
Fluvoxamine and Lonafarnib: major 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
Lonafarnib is a sensitive CYP3A4 substrate, and fluvoxamine is a weak to moderate CYP3A4 inhibitor. Exposure to lonafarnib may rise, increasing the risk of adverse effects such as gastrointestinal toxicity and QT prolongation.
What this interaction means in plain words
Fluvoxamine and Lonafarnib 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 belongs to Central Nervous System; Lonafarnib belongs to Miscellaneous.
Why it happens
Fluvoxamine inhibits CYP3A4, reducing lonafarnib metabolism.
What to do
Avoid if possible; otherwise monitor tolerability and ECG and lower the lonafarnib dose if adverse effects occur. Consider an antidepressant with less CYP3A4 inhibition.
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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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 Lonafarnib
- Alfuzosin + Lonafarnib Contraindicated
- Amobarbital + Lonafarnib Contraindicated
- Apalutamide + Lonafarnib Contraindicated
- Bosentan + Lonafarnib Contraindicated
- Carbamazepine + Lonafarnib Contraindicated
- Clarithromycin + Lonafarnib Contraindicated
Frequently asked questions
Can I take Fluvoxamine with Lonafarnib?
MediHelp rates the interaction as major. Fluvoxamine and Lonafarnib 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. Lonafarnib is a sensitive CYP3A4 substrate, and fluvoxamine is a weak to moderate CYP3A4 inhibitor. Exposure to lonafarnib may rise, increasing the risk of adverse effects such as gastrointestinal toxicity and QT prolongation.
How serious is the interaction between Fluvoxamine and Lonafarnib?
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 if possible; otherwise monitor tolerability and ECG and lower the lonafarnib dose if adverse effects occur. Consider an antidepressant with less CYP3A4 inhibition.
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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