Drug interactions
Fluoxetine + Losartan
Severity: Minor
Fluoxetine and Losartan: minor 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 inhibits CYP2C9 and may reduce conversion of losartan to its more potent active metabolite. The clinical effect is uncertain and probably small.
What this interaction means in plain words
Fluoxetine and Losartan have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Fluoxetine belongs to Central Nervous System; Losartan belongs to Cardiovascular.
Why it happens
CYP2C9 inhibition by fluoxetine may reduce formation of the active metabolite E-3174.
What to do
Monitor blood pressure when fluoxetine is started or stopped and adjust the losartan dose to response.
What to ask your pharmacist
- Is there anything I should notice while taking both?
- Do I need to tell my doctor at the next visit?
Pro+ members
Unlock the full page
Create an account and start a Pro+ trial to unlock the full management advice for Fluoxetine and Losartan, the additional notes, the evidence detail and the whole-prescription interaction checker.
- Full clinical management advice
- Additional notes
- Evidence detail
- Interaction checker for a whole prescription
Try Pro+ free for 7 days on the web. No card needed.
Other interactions of Losartan
- Aliskiren + Losartan Contraindicated
- Losartan + Sparsentan Contraindicated
- Amifostine + Losartan Major
- Amiloride + Losartan Major
- Amlodipine-benazepril + Losartan Major
- Amlodipine-hydrochlorothiazide-valsartan + Losartan 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 Losartan?
MediHelp rates the interaction as minor. Fluoxetine and Losartan have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Fluoxetine inhibits CYP2C9 and may reduce conversion of losartan to its more potent active metabolite. The clinical effect is uncertain and probably small.
How serious is the interaction between Fluoxetine and Losartan?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Monitor blood pressure when fluoxetine is started or stopped and adjust the losartan dose to response.
What other medicines interact with Losartan?
MediHelp also lists interactions of Losartan with, for example, Aliskiren, Sparsentan, Amifostine. The full list is on the Losartan page.
Full monographs, dosing and an interaction checker in the MediHelp app
Open the complete reference, check multi-drug interactions and use dosing tools in the MediHelp app.
