Fluconazole and Rifampin interaction

Fluconazole and Rifampin: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.

Major

Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.

What the FDA labels say

From the Rifampin (Rifadin IV) label · effective 2026-05-27

Major

…Prevention or Management: Perform prothrombin time daily or as frequently as necessary to establish and maintain the required dose of anticoagulant Warfarin Decrease exposure Antifungals Fluconazole Decrease AUC by 23% Itraconazole Prevention or Management: Not recommended 2 weeks before and during itraconazole treatment Decrease exposure Ketoconazole Decrease exposure…

Drug interactionsnames FluconazoleView label on DailyMed

From the Fluconazole label · effective 2026-04-02

Moderate

(See CLINICAL PHARMACOLOGY: Drug Interaction Studies .) Rifampin Rifampin enhances the metabolism of concurrently administered fluconazole.

Drug interactionsnames RifampinView label on DailyMed
Moderate

Depending on clinical circumstances, consideration should be given to increasing the dose of fluconazole when it is administered with rifampin.

Drug interactionsnames RifampinView label on DailyMed

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Not 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.