Oxybutynin and Carbamazepine Interaction

Drug interaction information between Oxybutynin and Carbamazepine.

Oxybutynin and Carbamazepine have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Oxybutynin and Carbamazepine. 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

Oxybutynin

Anticholinergic / Antispasmodic

Drug B

Carbamazepine

Anticonvulsant

How They Interact

Oxybutynin can increase the amount of carbamazepine in your blood by slowing down its removal from your body.

FDA Label Information

Drugs that have been shown, or would be expected, to increase plasma carbamazepine levels include aprepitant, cimetidine, ciprofloxacin, danazol, diltiazem, macrolides (e.g., erythromycin, clarithromycin), fluoxetine, fluvoxamine, trazodone, omeprazole, oxybutynin, isoniazid, niacinamide (nicotinamide), azoles (e.g., ketaconazole, itraconazole, fluconazole, voriconazole), acetazolamide, verapamil, ticlopidine, grapefruit juice, and protease inhibitors.

Frequently Asked Questions

What SPL severity band is on file for Oxybutynin + Carbamazepine?

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?

Carbamazepine has 129 labeled pairs on file vs Oxybutynin's 7. In the minor band specifically: Oxybutynin has 7 (also Ketoconazole, Erythromycin, Clarithromycin, Itraconazole); Carbamazepine has 110 (also Omeprazole, Ibuprofen, Citalopram, Amitriptyline).

What mechanism field is on file for Oxybutynin and Carbamazepine?

Oxybutynin can increase the amount of carbamazepine in your blood by slowing down its removal from your body.

Carbamazepine carries more major-labeled pairs than Oxybutynin

SPL source-record counts only. This page's band is minor · classes on file: Oxybutynin (Anticholinergic / Antispasmodic); Carbamazepine (Anticonvulsant).

Carbamazepine has 3 major-labeled pairs vs Oxybutynin's 0. This page itself is in the minor band, not the major band.

Oxybutynin

0 major · 0 moderate · 7 minor · 7 total

Carbamazepine

3 major · 16 moderate · 110 minor · 129 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.