Liothyronine and Carbamazepine Interaction

Drug interaction information between Liothyronine and Carbamazepine.

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

FDA drug labeling documents a minor-severity interaction between Liothyronine 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

Liothyronine

Thyroid Hormone (T3)

Drug B

Carbamazepine

Anticonvulsant

How They Interact

Carbamazepine knocks thyroid hormones off the proteins that carry them in the blood. This can lower the hormone levels seen on blood tests.

FDA Label Information

Other drugs: Carbamazepine Furosemide (>80 mg IV) Heparin Hydantoins Non-Steroidal Anti-inflammatory Drugs - Fenamates These drugs may cause protein binding site displacement. Phenytoin and carbamazepine reduce serum protein binding of thyroid hormones, and total and FT4 may be reduced by 20% to 40%, but most patients have normal serum TSH levels and are clinically euthyroid.

Frequently Asked Questions

What SPL severity band is on file for Liothyronine + 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 Liothyronine's 17. In the minor band specifically: Liothyronine has 17 (also Levothyroxine, Sertraline, Furosemide, Propranolol); Carbamazepine has 110 (also Omeprazole, Ibuprofen, Citalopram, Amitriptyline).

What mechanism field is on file for Liothyronine and Carbamazepine?

Carbamazepine knocks thyroid hormones off the proteins that carry them in the blood. This can lower the hormone levels seen on blood tests.

Carbamazepine carries more major-labeled pairs than Liothyronine

SPL source-record counts only. This page's band is minor · classes on file: Liothyronine (Thyroid Hormone (T3)); Carbamazepine (Anticonvulsant).

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

Liothyronine

0 major · 0 moderate · 17 minor · 17 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.