Drug interactions
Fluoxetine + Marijuana
Severity: Minor
Fluoxetine and Marijuana: 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
Cannabis has been reported in case reports to cause mania or hypomania in patients taking fluoxetine. Cannabidiol may inhibit CYP2D6 and CYP2C19, which could raise fluoxetine levels, though the clinical importance is uncertain.
What this interaction means in plain words
Fluoxetine and Marijuana have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised.
Why it happens
Possible CYP2D6 and CYP2C19 inhibition by cannabinoids, plus additive CNS effects.
What to do
Ask patients about cannabis use and monitor for mood elevation, anxiety and sedation. Counsel against heavy use.
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 Marijuana, 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 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 Marijuana?
MediHelp rates the interaction as minor. Fluoxetine and Marijuana have a small, usually unimportant interaction. Most people can take both; the pharmacist may still mention it so that any unexpected effect is recognised. Cannabis has been reported in case reports to cause mania or hypomania in patients taking fluoxetine. Cannabidiol may inhibit CYP2D6 and CYP2C19, which could raise fluoxetine levels, though the clinical importance is uncertain.
How serious is the interaction between Fluoxetine and Marijuana?
MediHelp rates it minor, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Ask patients about cannabis use and monitor for mood elevation, anxiety and sedation. Counsel against heavy use.
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.
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.
