Thioridazine and Darifenacin Interaction

Drug interaction information between Thioridazine and Darifenacin.

Thioridazine and Darifenacin have a documented moderate interaction in FDA labeling.

FDA drug labeling documents a moderate-severity interaction between Thioridazine and Darifenacin. 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

Thioridazine

Typical Antipsychotic (Phenothiazine)

Drug B

Darifenacin

Anticholinergic (Overactive Bladder)

How They Interact

Darifenacin can slow down the way your body breaks down thioridazine. This can cause thioridazine to build up to unsafe levels in your blood, which may lead to dangerous side effects.

FDA Label Information

7 DRUG INTERACTIONS Caution should be taken when darifenacin extended-release tablets are used concomitantly with medications that are predominantly metabolized by CYP2D6 and which have a narrow therapeutic window, such as flecainide, thioridazine and tricyclic antidepressants ( 7.2 ) The concomitant use of darifenacin extended-release tablets with other anticholinergic agents may increase the frequency and/or severity of dry mouth, constipation, blurred vision and other anticholinergic pharmacological effects. 7.3 CYP2D6 Substrates Caution should be taken when darifenacin extended-release...

Frequently Asked Questions

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

Compiled FDA labeling labels this pair moderate. That is a source-record field, not an individual medication-combination decision.

Which drug in this pair has the larger labeled-interaction portfolio?

Darifenacin has 18 labeled pairs on file vs Thioridazine's 17. In the moderate band specifically: Thioridazine has 3 (also Abiraterone, Tetrabenazine); Darifenacin has 3 (also Flecainide, Itraconazole).

What mechanism field is on file for Thioridazine and Darifenacin?

Darifenacin can slow down the way your body breaks down thioridazine. This can cause thioridazine to build up to unsafe levels in your blood, which may lead to dangerous side effects.

Thioridazine carries more major-labeled pairs than Darifenacin

SPL source-record counts only. This page's band is moderate · classes on file: Thioridazine (Typical Antipsychotic (Phenothiazine)); Darifenacin (Anticholinergic (Overactive Bladder)).

Thioridazine has 3 major-labeled pairs vs Darifenacin's 0. This page itself is in the moderate band, not the major band.

Thioridazine

3 major · 3 moderate · 11 minor · 17 total

Darifenacin

0 major · 3 moderate · 15 minor · 18 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.