Isocarboxazid and Fluoxetine
Desk tier: Avoid together
Mechanism: MAOI × serotonergic (serotonin syndrome / hypertensive crisis)
“Fluoxetine and other SSRIs should therefore not be used in combination with Marplan”
Why this grade
Marplan (isocarboxazid) label, Contraindications
The Marplan (isocarboxazid) label lists this combination under Contraindications. CONTRAINDICATIONS: "Fluoxetine and other SSRIs should therefore not be used in combination with Marplan" Named in the label: "Fluoxetine" Retrieved from DailyMed 2026-10-19.
Marplan (isocarboxazid) label on DailyMedFDA boxed / safety communication
MAOI labels contraindicate serotonergic agents. Serotonin toxicity, hypertensive crisis.
Search DailyMed for IsocarboxazidPMID 25974703
2015 Clin Pharmacol Ther. CPIC SSRIs. Flip 2C19 on this desk for citalopram / escitalopram.
PMID 25974703 on PubMedAll pairs for Isocarboxazid · Fluoxetine
Educational reference only. Not FDA-cleared. The Prescribing Information governs.
Drug and product names are trademarks of their owners and are used only to identify the products.