Terbinafine and Rifampin Interaction

Drug interaction information between Terbinafine and Rifampin.

Terbinafine and Rifampin have a documented minor interaction in FDA labeling.

FDA drug labeling documents a minor-severity interaction between Terbinafine and Rifampin. 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

Terbinafine

Allylamine Antifungal

Drug B

Rifampin

Rifamycin Antibiotic

How They Interact

Rifampin triggers the body to break down terbinafine twice as fast as usual.

FDA Label Information

Drug interactions have also been noted with cimetidine, fluconazole, cyclosporine, rifampin, and caffeine. Terbinafine clearance is increased 100% by rifampin, a CYP450 enzyme inducer, and decreased 33% by cimetidine, a CYP450 enzyme inhibitor.

Frequently Asked Questions

What SPL severity band is on file for Terbinafine + Rifampin?

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?

Rifampin has 137 labeled pairs on file vs Terbinafine's 17. In the minor band specifically: Terbinafine has 16 (also Ketoconazole, Fluconazole, Cyclosporine, Trimethoprim); Rifampin has 103 (also Metoprolol, Losartan, Simvastatin, Glipizide).

What mechanism field is on file for Terbinafine and Rifampin?

Rifampin triggers the body to break down terbinafine twice as fast as usual.

Rifampin carries more major-labeled pairs than Terbinafine

SPL source-record counts only. This page's band is minor · classes on file: Terbinafine (Allylamine Antifungal); Rifampin (Rifamycin Antibiotic).

Rifampin has 8 major-labeled pairs vs Terbinafine's 0. This page itself is in the minor band, not the major band.

Terbinafine

0 major · 1 moderate · 16 minor · 17 total

Rifampin

8 major · 26 moderate · 103 minor · 137 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.