Drug interactions
Fluoxetine + Tamsulosin
Severity: Moderate
Fluoxetine and Tamsulosin: 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 is a strong CYP2D6 inhibitor and can substantially increase tamsulosin concentrations. This may lead to dizziness, orthostatic hypotension and syncope, and the effect persists for weeks after fluoxetine is stopped.
What this interaction means in plain words
Fluoxetine and Tamsulosin 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; Tamsulosin belongs to Genitourinary.
Why it happens
Fluoxetine and its metabolite norfluoxetine inhibit CYP2D6, decreasing tamsulosin metabolism.
What to do
Monitor blood pressure and orthostatic symptoms, and consider a lower tamsulosin dose. Keep the long half-life of norfluoxetine in mind when stopping or switching.
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 Tamsulosin
- Alfuzosin + Tamsulosin Major
- Avanafil + Tamsulosin Major
- Ceritinib + Tamsulosin Major
- Clarithromycin + Tamsulosin Major
- Cobicistat + Tamsulosin Major
- Doxazosin + Tamsulosin Major
Other interactions of Fluoxetine
- Fluoxetine + Isocarboxazid Contraindicated
- Fluoxetine + Mavacamten Contraindicated
- Fluoxetine + Methylene blue Contraindicated
- Fluoxetine + Phenelzine Contraindicated
- Fluoxetine + Pimozide Contraindicated
- Fluoxetine + Rasagiline Contraindicated
Frequently asked questions
Can I take Fluoxetine with Tamsulosin?
MediHelp rates the interaction as moderate. Fluoxetine and Tamsulosin 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 is a strong CYP2D6 inhibitor and can substantially increase tamsulosin concentrations. This may lead to dizziness, orthostatic hypotension and syncope, and the effect persists for weeks after fluoxetine is stopped.
How serious is the interaction between Fluoxetine and Tamsulosin?
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 blood pressure and orthostatic symptoms, and consider a lower tamsulosin dose. Keep the long half-life of norfluoxetine in mind when stopping or switching.
What other medicines interact with Tamsulosin?
MediHelp also lists interactions of Tamsulosin with, for example, Alfuzosin, Avanafil, Ceritinib. The full list is on the Tamsulosin page.
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