Atomoxetine and Fluoxetine Interaction
Drug interaction information between Atomoxetine and Fluoxetine.
Atomoxetine and Fluoxetine have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Atomoxetine and Fluoxetine. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Fluoxetine blocks the liver enzyme that breaks down atomoxetine, which causes the levels of atomoxetine in your blood to rise significantly.
FDA Label Information
7.2 Effect of CYP2D6 Inhibitors on Atomoxetine In extensive metabolizers (EMs), inhibitors of CYP2D6 (e.g., paroxetine, fluoxetine, and quinidine) increase atomoxetine steady-state plasma concentrations to exposures similar to those observed in poor metabolizers (PMs). In EM individuals treated with paroxetine or fluoxetine, the AUC of atomoxetine is approximately 6- to 8-fold and C ss, max is about 3- to 4-fold greater than atomoxetine alone.
Atomoxetine Also Interacts With
- Albuterol moderate
- Omeprazole minor
- Methylphenidate minor
- Warfarin minor
- Diazepam minor
Fluoxetine Also Interacts With
- Aspirin major
- Warfarin major
- Olanzapine major
- Pimozide major
- Thioridazine major
Frequently Asked Questions
What SPL severity band is on file for Atomoxetine + Fluoxetine?
Compiled FDA labeling labels this pair minor. That is a source-record field, not an individual medication-combination decision.
Which drug in this pair has the larger labeled-interaction portfolio?
Fluoxetine has 68 labeled pairs on file vs Atomoxetine's 15. In the minor band specifically: Atomoxetine has 14 (also Omeprazole, Methylphenidate, Warfarin, Diazepam); Fluoxetine has 43 (also Ketoconazole, Lithium, Moxifloxacin, Erythromycin).
What mechanism field is on file for Atomoxetine and Fluoxetine?
Fluoxetine blocks the liver enzyme that breaks down atomoxetine, which causes the levels of atomoxetine in your blood to rise significantly.
Fluoxetine carries more major-labeled pairs than Atomoxetine
SPL source-record counts only. This page's band is minor · classes on file: Atomoxetine (Selective Norepinephrine Reuptake Inhibitor); Fluoxetine (Selective Serotonin Reuptake Inhibitor (SSRI)).
Fluoxetine has 6 major-labeled pairs vs Atomoxetine's 0. This page itself is in the minor band, not the major band.
0 major · 1 moderate · 14 minor · 15 total
- Other minor peers for Atomoxetine
- Omeprazole
- Methylphenidate
- Warfarin
- Diazepam
6 major · 19 moderate · 43 minor · 68 total
- Other minor peers for Fluoxetine
- Ketoconazole
- Lithium
- Moxifloxacin
- Erythromycin
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. This registry does not provide individual medication-combination directions.
Read our methodology - how this data is sourced, computed, and verified.