Drug interactions
Fluoxetine + Toremifene
Severity: Major
Fluoxetine and Toremifene: major interaction.
Last updated Sources: US FDA label
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
Toremifene causes dose-related QT prolongation and fluoxetine adds to this effect. Toremifene labeling advises against combination with other QT-prolonging drugs because of torsades de pointes risk.
What this interaction means in plain words
Fluoxetine and Toremifene 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.
Fluoxetine belongs to Central Nervous System; Toremifene belongs to Endocrine.
Why it happens
Additive prolongation of cardiac repolarization.
What to do
Avoid the combination where possible and use an alternative antidepressant with less QT effect. If it is unavoidable, monitor ECG and keep potassium and magnesium normal.
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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References
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 Toremifene
- Amiodarone + Toremifene Contraindicated
- Dronedarone + Toremifene Contraindicated
- Nilotinib + Toremifene Contraindicated
- Pimozide + Toremifene Contraindicated
- Quinidine + Toremifene Contraindicated
- Ribociclib + Toremifene Contraindicated
Frequently asked questions
Can I take Fluoxetine with Toremifene?
MediHelp rates the interaction as major. Fluoxetine and Toremifene 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. Toremifene causes dose-related QT prolongation and fluoxetine adds to this effect. Toremifene labeling advises against combination with other QT-prolonging drugs because of torsades de pointes risk.
How serious is the interaction between Fluoxetine and Toremifene?
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 the combination where possible and use an alternative antidepressant with less QT effect. If it is unavoidable, monitor ECG and keep potassium and magnesium normal.
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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