Fluconazole and Venlafaxine interaction
Fluconazole and Venlafaxine: both prescribing labels flag this combination with the strongest language, such as a contraindication, a boxed warning, or an instruction to avoid it.
Do not combine without a prescriber's guidance. The label language below is the strongest FDA uses.
What the FDA labels say
From the Fluconazole label · effective 2026-04-02
Coadministration of other drugs known to prolong the QT interval and which are metabolized via the enzyme CYP3A4 such as erythromycin, pimozide, and quinidine are contraindicated in patients receiving fluconazole.
From the Venlafaxine (Venlafaxine Hydrochloride) label · effective 2025-01-31
Concomitant use of CYP3A4 inhibitors and venlafaxine may increase levels of venlafaxine and ODV.
Therefore, caution is advised if a patient’s therapy includes a CYP3A4 inhibitor and venlafaxine concomitantly.
CYP3A4 Venlafaxine did not inhibit CYP3A4 in vitro .
CYP2C9 Venlafaxine did not inhibit CYP2C9 in vitro .
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.