What the FDA labels say about taking them together
Fluoxetine and thioridazine
Fluoxetine's FDA label of January 8, 2026 names thioridazine in its contraindications section, and thioridazine's label names fluoxetine too. The fluoxetine label: “Pimozide and thioridazine are contraindicated for use with PROZAC.”
Check it at the source: the fluoxetine FDA label on DailyMed (effective January 8, 2026, Dista Products Company); the thioridazine FDA label on DailyMed (effective November 11, 2025, Mylan Institutional Inc.).
What does the fluoxetine label say about thioridazine?
Fluoxetine label, contraindicationsRisk of QT prolongation and drug interaction ( 4.2 , 5.11 , 7.7 , 7.8 ) Thioridazine: Risk of QT interval prolongation and elevated thioridazine plasma levels.
Fluoxetine label, drug interactionsThioridazine – Thioridazine should not be administered with PROZAC or within a minimum of 5 weeks after PROZAC has been discontinued, because of the risk of QT Prolongation [see Contraindications ( 4.2 ), Warnings and Precautions ( 5.11 ), and Drug Interactions ( 7.8 )].
Fluoxetine label, warnings and precautionsPimozide and thioridazine are contraindicated for use with PROZAC.
Source: FDA drug label (Prozac), NDA018936 (Eli Lilly And Co), as published by Dista Products Company, effective January 8, 2026 (SPL set c88f33ed-6dfb-4c5e-bc01-d8e36dd97299), via openFDA; the full label on DailyMed
What does the thioridazine label say about fluoxetine?
Thioridazine label, contraindicationsReduced cytochrome P450 2D6 isozyme activity drugs that inhibit this isozyme (e.g., fluoxetine and paroxetine) and certain other drugs (e.g., fluvoxamine, propranolol, and pindolol) appear to appreciably inhibit the metabolism of thioridazine.
Source: FDA drug label (Thioridazine Hydrochloride), Mylan Institutional Inc., effective November 11, 2025 (SPL set 52fea941-0b47-41c1-b00d-f88150e8ab93), via openFDA; the full label on DailyMed
These are the labels' own sentences. PlainMeds does not grade interactions; a pharmacist or prescriber can say what they mean for one person's medicines.
Both medicines on the record
| Fluoxetine | Thioridazine | |
|---|---|---|
| Labeled for | Depression, Anxiety, Bipolar disorder | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.0519 per capsule 40 mg capsule | $0.571 per tablet 25 mg tablet |
| Shortage now | No current entry | No current entry |
Source: FDA NDC Directory, CMS NADAC of October 7, 2026 and the FDA Drug Shortage Database (FDA files October 8, 2026)
What next?
- Check more medicines together
- up to five at once