Fluoxetine and Phenelzine: Drug Interaction Guide
Quick answer: This is a major interaction — avoid combining Fluoxetine and Phenelzine unless specifically directed by your doctor.
How Fluoxetine interacts with Phenelzine
Fluoxetine increases serotonergic neurotransmission, while phenelzine inhibits monoamine oxidase and prevents serotonin breakdown. Combined use can precipitate serotonin syndrome.
What you should do
Contraindicated. Use an adequate washout period, including a longer interval after fluoxetine because of its long-lived active metabolite norfluoxetine.
Key facts
Severity
Major — avoid combination
Mechanism
Fluoxetine increases serotonergic neurotransmission, while phenelzine inhibits monoamine oxidase and prevents serotonin ...
Action
Contraindicated. Use an adequate washout period, including a longer interval after fluoxetine because of its long-lived ...
Frequently asked questions
Can I take Fluoxetine and Phenelzine together?
No — this combination should generally be avoided. Contraindicated. Use an adequate washout period, including a longer interval after fluoxetine because of its long-lived active metabolite norfluoxetine.
What is the severity of this interaction?
The interaction between Fluoxetine and Phenelzine is classified as Major — avoid combination. Fluoxetine increases serotonergic neurotransmission, while phenelzine inhibits monoamine oxidase and prevents serotonin breakdown. Combined use can precipitate serotonin syndrome.
What should I do if I'm prescribed both?
Contraindicated. Use an adequate washout period, including a longer interval after fluoxetine because of its long-lived active metabolite norfluoxetine. Always consult your prescribing clinician — do not stop or change medications without medical guidance.
Last reviewed: by iMedic Medical Editorial Team. Our editorial process.