Fluoxetine and Pimozide Interaction
Drug interaction information between Fluoxetine and Pimozide.
Fluoxetine and Pimozide have a documented major interaction in FDA labeling.
FDA drug labeling documents a major-severity interaction between Fluoxetine and Pimozide. Major interactions are generally avoided, moderate ones may need monitoring or a dose adjustment, and minor ones are usually low-risk. This page shows the documented mechanism and guidance. Label-documented interactions are not a complete safety review, so always confirm your own medications with a pharmacist or doctor. Educational information, not medical advice.
How They Interact
Taking these two drugs together can cause dangerous changes to the electrical rhythm of your heart. This is known as QT prolongation and can be very serious.
What To Do
Do not take these two medications together because the risk to your heart is too high.
FDA Label Information
NSAIDs, Aspirin, Warfarin): May potentiate the risk of bleeding ( 7.4 ) Drugs Tightly Bound to Plasma Proteins: May cause a shift in plasma concentrations ( 7.6 , 7.7 ) Olanzapine: When used in combination with fluoxetine, also refer to the Drug Interactions section of the package insert for Symbyax ( 7.7 ) Drugs that Prolong the QT Interval: Do not use fluoxetine with thioridazine or pimozide. 7.7 Potential for Fluoxetine to affect Other Drugs Pimozide — Concomitant use in patients taking pimozide is contraindicated. Pimozide can prolong the QT interval.
Fluoxetine Also Interacts With
- Aspirin major
- Warfarin major
- Olanzapine major
- Thioridazine major
- Clonazepam major
Pimozide Also Interacts With
- Aprepitant major
- Citalopram major
- Clarithromycin major
- Darunavir major
- Escitalopram major
Frequently Asked Questions
Can I take Fluoxetine and Pimozide together?
This is a major interaction. Do not take these two medications together because the risk to your heart is too high.
How serious is the interaction between Fluoxetine and Pimozide?
This interaction is classified as "major" severity by the FDA. Major interactions may be life-threatening or cause serious side effects.
Why do Fluoxetine and Pimozide interact?
Taking these two drugs together can cause dangerous changes to the electrical rhythm of your heart. This is known as QT prolongation and can be very serious.
Understanding the Fluoxetine and Pimozide Interaction
FDA-approved prescribing information for these two drugs flags their combination as a major-severity interaction. Fluoxetine belongs to the Selective Serotonin Reuptake Inhibitor (SSRI) class and Pimozide belongs to the Typical Antipsychotic class - two categories that can collide when co-prescribed. The mechanism described in FDA labeling is: Taking these two drugs together can cause dangerous changes to the electrical rhythm of your heart. Severity tiers matter: major flags generally advise avoidance, moderate flags often require monitoring or dose adjustment, and minor flags may only call for awareness.
Context around a specific patient determines real-world impact. Fluoxetine has 68 total documented interactions on file in this dataset, and Pimozide has 24. Each additional medication compounds the interaction surface, which is why pharmacists run full-profile checks rather than evaluating one pair at a time. FDA-derived guidance for this pair is: Do not take these two medications together because the risk to your heart is too high. Timing of doses, renal and hepatic function, age, and other concurrent prescriptions all shape whether a labeled interaction matters clinically.
An interaction flag is not a verdict. A large share of labeled interactions are managed routinely in clinical practice, the fix may be as simple as spacing doses or adding a monitoring test. Others require the prescriber to choose a different medication entirely. This page surfaces FDA-sourced labeling and openFDA data for educational purposes only; it is not medical advice and cannot account for your full clinical picture. Never start, stop, or adjust either Fluoxetine or Pimozide based on a web page, speak with your prescriber or pharmacist before making any change.
Sources: FDA Drug Labels (SPL) via openFDA (2026). This is for informational purposes only and is not medical advice. Always consult your healthcare provider about drug interactions.
Read our methodology - how this data is sourced, computed, and verified.