What the FDA labels say about taking them together
Paroxetine and thioridazine
Paroxetine's FDA label of February 12, 2026 names thioridazine in its contraindications section, and thioridazine's label names paroxetine too. The paroxetine label: “Concomitant use of thioridazine and BRISDELLE is contraindicated.”
Check it at the source: the paroxetine FDA label on DailyMed (effective February 12, 2026, Mylan Pharmaceuticals Inc.); the thioridazine FDA label on DailyMed (effective November 11, 2025, Mylan Institutional Inc.).
What does the paroxetine label say about thioridazine?
Paroxetine label, contraindicationsTaking thioridazine because of risk of QT prolongation [see Warnings and Precautions (5.3), Drug Interactions (7) ].
Paroxetine label, drug interactionsClinical Impact; Increased plasma concentrations of pimozide and thioridazine, drugs with a narrow therapeutic index, may increase the risk of QTc prolongation and ventricular arrhythmias.
Paroxetine label, warnings and precautionsLeading to QT Prolongation The CYP2D6 inhibitory properties of paroxetine can elevate plasma levels of thioridazine and pimozide.
Paroxetine Hydrochloride label (Apotex Corp, September 16, 2026), contraindicationsParoxetine HCL CR should not be used in patients receiving medications that can prolong QT interval and are also metabolized by CYP450 2D6,such as thioridazine or pimozide [see Drug Interactions (7),Warnings and Precautions (5.3)].
Source: FDA drug label (Paroxetine Hydrochloride, NDA020936), Apotex Corp, effective September 16, 2026 (SPL set 087ff0d3-1761-47ea-a8c1-7c4cb679af97), via openFDA
Source: FDA drug label (Paroxetine), Mylan Pharmaceuticals Inc., effective February 12, 2026 (SPL set 89dd7e24-85fc-4152-89ea-47ec2b48a1ed), via openFDA; the full label on DailyMed
What does the thioridazine label say about paroxetine?
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
| Paroxetine | Thioridazine | |
|---|---|---|
| Labeled for | Depression, Anxiety, Menopause symptoms | n/a |
| Boxed warning | Yes | Yes |
| Pharmacy cost (NADAC) | $0.0611 per tablet 20 mg tablet | $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