Pimozide and Thioridazine Interaction

Drug interaction information between Pimozide and Thioridazine.

Pimozide and Thioridazine have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Pimozide and Thioridazine. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.

Drug A

Pimozide

Typical Antipsychotic

Drug B

Thioridazine

Typical Antipsychotic (Phenothiazine)

How They Interact

These medications both slow down the electrical signals in your heart. This shared effect can cause the heart to beat in an unsafe way.

FDA Label Information

Accordingly, pimozide should not be given with dofetilide, sotalol, quinidine, other Class Ia and III anti-arrhythmics, mesoridazine, thioridazine, chlorpromazine, droperidol, sparfloxacin, gatifloxacin, moxifloxacin, halofantrine, mefloquine, pentamidine, arsenic trioxide, levomethadyl acetate, dolasetron mesylate, probucol, tacrolimus, ziprasidone, or other drugs that have demonstrated QT prolongation as one of their pharmacodynamic effects.

Frequently Asked Questions

What SPL severity band is on file for Pimozide + Thioridazine?

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?

Pimozide has 24 labeled pairs on file vs Thioridazine's 17. In the minor band specifically: Pimozide has 12 (also Moxifloxacin, Ziprasidone, Chlorpromazine, Sotalol); Thioridazine has 11 (also Propranolol, Pindolol, Bupropion, Carbamazepine).

What mechanism field is on file for Pimozide and Thioridazine?

These medications both slow down the electrical signals in your heart. This shared effect can cause the heart to beat in an unsafe way.

Pimozide carries more major-labeled pairs than Thioridazine

SPL source-record counts only. This page's band is minor · classes on file: Pimozide (Typical Antipsychotic); Thioridazine (Typical Antipsychotic (Phenothiazine)).

Pimozide has 12 major-labeled pairs vs Thioridazine's 3. This page itself is in the minor band, not the major band.

Pimozide

12 major · 0 moderate · 12 minor · 24 total

Thioridazine

3 major · 3 moderate · 11 minor · 17 total

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.