Drug interactions
Cobicistat + Fluoxetine
Severity: Moderate
Cobicistat 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
Cobicistat is a strong CYP3A4 and CYP2D6 inhibitor, and fluoxetine is metabolized in part by CYP2D6 and 3A4. Fluoxetine exposure may increase, with more serotonergic and other adverse effects.
What this interaction means in plain words
Cobicistat 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.
Cobicistat belongs to Miscellaneous; Fluoxetine belongs to Central Nervous System.
Why it happens
Inhibition of CYP2D6 and CYP3A4 by cobicistat reducing fluoxetine clearance.
What to do
Titrate fluoxetine carefully using the lowest effective dose and monitor for adverse effects and clinical response. Watch for signs of serotonin toxicity.
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 Cobicistat
- Alfuzosin + Cobicistat Contraindicated
- Apalutamide + Cobicistat Contraindicated
- Cobicistat + Colchicine Contraindicated
- Cobicistat + Dronedarone Contraindicated
- Cobicistat + Eletriptan Contraindicated
- Cobicistat + Eplerenone Contraindicated
Frequently asked questions
Can I take Cobicistat with Fluoxetine?
MediHelp rates the interaction as moderate. Cobicistat 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. Cobicistat is a strong CYP3A4 and CYP2D6 inhibitor, and fluoxetine is metabolized in part by CYP2D6 and 3A4. Fluoxetine exposure may increase, with more serotonergic and other adverse effects.
How serious is the interaction between Cobicistat 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: Titrate fluoxetine carefully using the lowest effective dose and monitor for adverse effects and clinical response. Watch for signs of serotonin toxicity.
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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