Drug interactions
Fluoxetine + Lonafarnib
Severity: Moderate
Fluoxetine and Lonafarnib: 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
Lonafarnib is a sensitive CYP3A4 substrate, and fluoxetine is a weak CYP3A4 inhibitor that may increase lonafarnib exposure. Higher exposure raises the risk of lonafarnib toxicity such as gastrointestinal effects, and its effect on the QT interval is uncertain.
What this interaction means in plain words
Fluoxetine and Lonafarnib 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.
Fluoxetine belongs to Central Nervous System; Lonafarnib belongs to Miscellaneous.
Why it happens
Weak inhibition of CYP3A4-mediated lonafarnib metabolism by fluoxetine.
What to do
Continue lonafarnib at the current or starting dose rather than escalating. Monitor for toxicity, arrhythmia symptoms and QTc.
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 Fluoxetine
- Fluoxetine + Isocarboxazid Contraindicated
- Fluoxetine + Mavacamten Contraindicated
- Fluoxetine + Methylene blue Contraindicated
- Fluoxetine + Phenelzine Contraindicated
- Fluoxetine + Pimozide Contraindicated
- Fluoxetine + Rasagiline 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 Fluoxetine with Lonafarnib?
MediHelp rates the interaction as moderate. Fluoxetine and Lonafarnib 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. Lonafarnib is a sensitive CYP3A4 substrate, and fluoxetine is a weak CYP3A4 inhibitor that may increase lonafarnib exposure. Higher exposure raises the risk of lonafarnib toxicity such as gastrointestinal effects, and its effect on the QT interval is uncertain.
How serious is the interaction between Fluoxetine and Lonafarnib?
MediHelp rates it moderate, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Continue lonafarnib at the current or starting dose rather than escalating. Monitor for toxicity, arrhythmia symptoms and QTc.
What other medicines interact with Fluoxetine?
MediHelp also lists interactions of Fluoxetine with, for example, Isocarboxazid, Mavacamten, Methylene blue. The full list is on the Fluoxetine page.
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