Drug interactions
Fluoxetine + Methylenedioxymethamphetamine
Severity: Major
Fluoxetine and Methylenedioxymethamphetamine: 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
Fluoxetine inhibits CYP2D6, which contributes to MDMA metabolism, and it also affects serotonin transport. This can alter MDMA effects and raise the risk of serotonin syndrome, hyperthermia and cardiovascular toxicity.
What this interaction means in plain words
Fluoxetine and Methylenedioxymethamphetamine 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.
Why it happens
CYP2D6 inhibition slows MDMA clearance, and additive serotonergic activity increases serotonin toxicity risk.
What to do
Advise patients to avoid MDMA while taking fluoxetine, since its inhibitory effect persists for weeks after discontinuation. Treat suspected toxicity as serotonin syndrome with supportive care and urgent medical assessment.
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
Frequently asked questions
Can I take Fluoxetine with Methylenedioxymethamphetamine?
MediHelp rates the interaction as major. Fluoxetine and Methylenedioxymethamphetamine 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 inhibits CYP2D6, which contributes to MDMA metabolism, and it also affects serotonin transport. This can alter MDMA effects and raise the risk of serotonin syndrome, hyperthermia and cardiovascular toxicity.
How serious is the interaction between Fluoxetine and Methylenedioxymethamphetamine?
MediHelp rates it major, on a four-level scale (minor, moderate, major, contraindicated) based on published labels and references. What to do, in brief: Advise patients to avoid MDMA while taking fluoxetine, since its inhibitory effect persists for weeks after discontinuation. Treat suspected toxicity as serotonin syndrome with supportive care and urgent medical assessment.
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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