Drug interactions
Carbamazepine + Fluoxetine
Severity: Moderate
Carbamazepine and Fluoxetine: 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
Fluoxetine can increase carbamazepine concentrations, with reports of toxicity such as dizziness, ataxia, nausea and diplopia. Fluoxetine also lowers seizure threshold and may contribute to hyponatremia in combination with carbamazepine.
What this interaction means in plain words
Carbamazepine and Fluoxetine 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.
Carbamazepine belongs to Central Nervous System; Fluoxetine belongs to Central Nervous System.
Why it happens
Fluoxetine inhibits CYP3A4 (and possibly other pathways) involved in carbamazepine metabolism.
What to do
Monitor carbamazepine serum levels and signs of toxicity after starting or changing fluoxetine, and check sodium; reduce the carbamazepine dose as needed.
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 Carbamazepine
- Artemether / lumefantrine + Carbamazepine Contraindicated
- Cabotegravir + Carbamazepine Contraindicated
- Carbamazepine + Delamanid Contraindicated
- Carbamazepine + Dienogest / estradiol valerate Contraindicated
- Carbamazepine + Doravirine Contraindicated
- Carbamazepine + Elbasvir / grazoprevir Contraindicated
Frequently asked questions
Can I take Carbamazepine with Fluoxetine?
MediHelp rates the interaction as moderate. Carbamazepine and Fluoxetine 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 can increase carbamazepine concentrations, with reports of toxicity such as dizziness, ataxia, nausea and diplopia. Fluoxetine also lowers seizure threshold and may contribute to hyponatremia in combination with carbamazepine.
How serious is the interaction between Carbamazepine and Fluoxetine?
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 carbamazepine serum levels and signs of toxicity after starting or changing fluoxetine, and check sodium; reduce the carbamazepine dose as needed.
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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