Liothyronine and Furosemide Interaction

Drug interaction information between Liothyronine and Furosemide.

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

FDA drug labeling documents a minor-severity interaction between Liothyronine and Furosemide. 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

Furosemide

Loop Diuretic

How They Interact

This water pill can knock thyroid hormones off the proteins they usually ride on in your blood, which changes the amount of active hormone in your body.

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. Furosemide has been shown to inhibit the protein binding of T4 to TBG and albumin, causing an increased free-T4 fraction in serum. Furosemide competes for T4-binding sites on TBG, prealbumin, and albumin, so that a single high dose can acutely lower the total T4 level.

Frequently Asked Questions

What SPL severity band is on file for Liothyronine + Furosemide?

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?

Furosemide has 36 labeled pairs on file vs Liothyronine's 17. In the minor band specifically: Liothyronine has 17 (also Levothyroxine, Sertraline, Propranolol, Amitriptyline); Furosemide has 29 (also Methotrexate, Norepinephrine, Ethacrynic Acid, Indomethacin).

What mechanism field is on file for Liothyronine and Furosemide?

This water pill can knock thyroid hormones off the proteins they usually ride on in your blood, which changes the amount of active hormone in your body.

Furosemide 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)); Furosemide (Loop Diuretic).

Furosemide 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

Furosemide

3 major · 4 moderate · 29 minor · 36 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.