Terbinafine and Trimethoprim Interaction
Drug interaction information between Terbinafine and Trimethoprim.
Terbinafine and Trimethoprim have a documented minor interaction in FDA labeling.
FDA drug labeling documents a minor-severity interaction between Terbinafine and Trimethoprim. This page displays the available source-record category and label text. The category is not an individual risk estimate or medication-combination direction.
How They Interact
Terbinafine does not significantly change how the body handles trimethoprim.
FDA Label Information
The influence of terbinafine on the pharmacokinetics of fluconazole, cotrimoxazole (trimethoprim and sulfamethoxazole), zidovudine or theophylline was not considered to be clinically significant.
Terbinafine Also Interacts With
- Tamsulosin moderate
- Ketoconazole minor
- Fluconazole minor
- Cyclosporine minor
- Rifampin minor
Trimethoprim Also Interacts With
- Theophylline major
- Prenatal Multivitamin moderate
- Spironolactone moderate
- Spironolactone (Acne) moderate
- Metformin minor
Frequently Asked Questions
What SPL severity band is on file for Terbinafine + Trimethoprim?
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?
Trimethoprim has 22 labeled pairs on file vs Terbinafine's 17. In the minor band specifically: Terbinafine has 16 (also Ketoconazole, Fluconazole, Cyclosporine, Rifampin); Trimethoprim has 18 (also Metformin, Glipizide, Warfarin, Methotrexate).
What mechanism field is on file for Terbinafine and Trimethoprim?
Terbinafine does not significantly change how the body handles trimethoprim.
Trimethoprim carries more major-labeled pairs than Terbinafine
SPL source-record counts only. This page's band is minor · classes on file: Terbinafine (Allylamine Antifungal); Trimethoprim (Dihydrofolate Reductase Inhibitor).
Trimethoprim has 1 major-labeled pair vs Terbinafine's 0. This page itself is in the minor band, not the major band.
0 major · 1 moderate · 16 minor · 17 total
- Other minor peers for Terbinafine
- Ketoconazole
- Fluconazole
- Cyclosporine
- Rifampin
1 major · 3 moderate · 18 minor · 22 total
- Other minor peers for Trimethoprim
- Metformin
- Glipizide
- Warfarin
- Methotrexate
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.
Read our methodology - how this data is sourced, computed, and verified.