Fluoxetine and Paroxetine interaction
Fluoxetine and Paroxetine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Fluoxetine (Prozac) label · effective 2026-01-08
If concomitant use of PROZAC with other serotonergic drugs is clinically warranted, patients should be made aware of a potential increased risk for serotonin syndrome, particularly during treatment initiation and dose increases ( 5.2 )
If concomitant use of PROZAC with other serotonergic drugs is clinically warranted, inform patients of the increased risk for serotonin syndrome and monitor for symptoms.
The risk is increased with concomitant use of other serotonergic drugs (including triptans, tricyclic antidepressants, fentanyl, lithium, tramadol, tryptophan, meperidine, methadone, buspirone, amphetamines, and St.
Clinical studies of pimozide with other antidepressants demonstrate an increase in drug interaction or QT prolongation.
Serotonin Syndrome: Serotonin syndrome has been reported with SSRIs and SNRIs, including PROZAC, both when taken alone, but especially when co-administered with other serotonergic agents.
From the Paroxetine (BRISDELLE) label · effective 2025-04-28
Serotonin Syndrome: BRISDELLE can cause serotonin syndrome with increased risk when co-administered with other serotonergic agents, but also when taken alone.
If concomitant use of BRISDELLE with other serotonergic drugs (besides MAOIs) is clinically warranted, consider the increased risk of serotonin syndrome and carefully observe the patient, particularly during BRISDELLE initiation [see Contraindications ( 4.1 )
Use caution with concomitant use of BRISDELLE with other drugs that are metabolized by CYP2D6, including nortriptyline, amitriptyline, imipramine, desipramine, fluoxetine, phenothiazines, risperidone, and Type 1C antiarrhythmics (e.g., propafenone, flecainide, and encainide).
The risk is increased with concomitant use of other serotonergic agents (including triptans, tricyclic antidepressants, fentanyl, tramadol, meperidine, methadone, lithium, tryptophan, buspirone, amphetamines, and St.
Cimetidine Increased plasma concentration of paroxetine Use caution if BRISDELLE is used concomitantly with other drugs that inhibit CYP2D6 (e.g., quinidine).
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.