Sulfamethoxazole and trimethoprim and Terbinafine interaction
Sulfamethoxazole and trimethoprim and Terbinafine: the Terbinafine prescribing label describe an interaction that usually calls for monitoring, a dose change, or spacing the doses.
Usually manageable with monitoring or a dose change. Tell your pharmacist you take both.
What the FDA labels say
From the Terbinafine (Terbinafine Hydrochloride) label · effective 2026-01-01
The influence of terbinafine on the pharmacokinetics of fluconazole, cotrimoxazole (trimethoprim and sulfamethoxazole), zidovudine or theophylline was not considered to be clinically significant.
Fluconazole is an inhibitor of CYP2C9 and CYP3A enzymes.
Taking more than these two? Interactions stack. Check your whole list at once; it stays in your browser.
Open in the checkerNot medical advice. Interaction Checker quotes FDA label text and NIH fact sheets. Whether an interaction matters for you depends on doses, timing, kidney and liver function, and other conditions. Confirm with a pharmacist or prescriber.